Body model composition update from two-dimensional face images

ABSTRACT

Described are systems and methods directed to generation and subsequent update of a dimensionally accurate body model of a body, such as a human body, based on two-dimensional (“2D”) images of at least a portion of that body and/or face images of a face of the body. A user may use a 2D camera, such as a digital camera typically included in many of today&#39;s portable devices (e.g., cell phones, tablets, laptops, etc.) to produce body images that are used to generate a body model of the body of the user. Subsequently, the body model may be updated based on a face image of the face of the user, without requiring the user to provide another body image.

BACKGROUND

Three-dimensional modeling of the human body currently requires large or expensive sensors, such as stereo imaging elements, three-dimensional scanners, depth sensing devices, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a transition diagram of processing two-dimensional body images to produce a dimensionally accurate body model of that body, in accordance with implementations of the present disclosure.

FIG. 1B is a transition diagram of processing two-dimensional face images to produce face-based body features that are used to update the body model generated as discussed with respect to FIG. 1A, in accordance with implementations of the present disclosure.

FIG. 1C is a diagram of an image of a body of a user with two-dimensional landmarks indicated both inside and outside of the image, in accordance with implementations of the present disclosure.

FIG. 2A is another transition diagram of processing two-dimensional body images to produce a dimensionally accurate body model of that body, in accordance with implementations of the present disclosure.

FIG. 2B is another transition diagram of processing two-dimensional body images to produce a dimensionally accurate body model of that body, in accordance with implementations of the present disclosure.

FIG. 2C is a transition diagram of processing two-dimensional face images to produce face-based predicted body features that are used to update an existing body model of a body, in accordance with implementations of the present disclosure.

FIG. 3 is a block diagram of components of an image processing system, in accordance with implementations of the present disclosure.

FIG. 4 is a block diagram of a trained body composition model that determines predicted body features of a body represented in two-dimensional body images, in accordance with implementations of the present disclosure.

FIG. 5 is an example flow diagram of a body model generation process, in accordance with implementations of the present disclosure.

FIG. 6A is an example flow diagram of a body model adjustment process, in accordance with implementations of the present disclosure.

FIG. 6B is another example flow diagram of a body model adjustment process, in accordance with implementations of the present disclosure.

FIG. 7 is an example flow diagram of a texturing process, in accordance with implementations of the present disclosure.

FIG. 8 is an example flow diagram of a body model update process, in accordance with implementations of the present disclosure.

FIG. 9 is an example flow diagram of a bias correction process, in accordance with implementations of the present disclosure.

DETAILED DESCRIPTION

As is set forth in greater detail below, implementations of the present disclosure are directed to generation of a dimensionally accurate body model of a body, such as a human body, based on two-dimensional (“2D”) images of at least a portion of that body, referred to herein as a 2D body image and subsequent update of that body model using face-based body features determined from face images of a face of the body. The term 2D body image, as used herein, refers to both 2D body images that include a representation of an entire body of a user as well as 2D body images that include a representation of only a portion of the 2D body (i.e., less than the entire body of the user). A 2D partial body image, as used herein, refers specifically to 2D images that include a representation of less than the entire body of the user. A face image, as used herein, corresponds to a face or head of a body of a user included in the image that is significantly devoid of other portions of the body. A body model, as used herein, may refer to a three-dimensional rendering of a body or other dimensional representation of the body.

In some implementations, a user, also referred to herein as a person, may use a 2D camera, such as a digital camera typically included in many of today's portable devices (e.g., cell phones, tablets, laptops, etc.) and obtain a series of 2D body images of their body from different views with respect to the camera. For example, the camera may be stationary, and the user may position themselves in a front view facing toward the camera and the camera may obtain one or more front view images of the body of the user. The user may then turn approximately ninety degrees to the right to a first side view facing the camera, and the camera may obtain one or more first side view images of the body of the user. The user may then turn approximately ninety degrees to the right to a back view facing the camera, and the camera may obtain one or more back view images of the body of the user. The user may then turn approximately ninety degrees to the right to a second side view facing the camera, and the camera may obtain one or more second side view images of the body of the user. As discussed further below, any number of body orientations with respect to the camera and corresponding images thereof may be obtained and used with the disclosed implementations.

As noted above, only a portion of the body need be visible and represented in the images. For example, the disclosed implementations may utilize images in which a portion of the body, such as the lower legs and feet, hands, and/or head are not represented in the image and/or are occluded by other objects represented in the image. Such 2D partial body images may be produced, for example, if the user is positioned such that a portion of the body of the user is outside the field of view of the camera. In other examples, if another object (e.g., table, desk) is between a portion of the body of the user and the camera, a 2D partial body image may be produced in which less than all of the body of the user is represented in the image. In still other examples, the position of the body of the user, such as kneeling, sitting, etc., when the images are generated may result in one or more 2D partial body images.

Two-dimensional body images of the different views of the body of the user may then be processed using one or more processing techniques, as discussed further below, to generate a plurality of predicted body features corresponding to the body of the user represented in the images. Those predicted body features may then be further processed, as discussed below, to generate a dimensionally accurate body model or avatar of the body of the user. In some implementations, the generated body model may be further adjusted to match the shape and/or size of the body of the user as represented in one or more of the original 2D body images. Likewise, or in addition thereto, in some implementations, one or more textures (e.g., skin color, clothing, hair, facial features, etc.) may be determined from the original 2D body images and used to augment the body model of the user, thereby generating a dimensionally accurate and visually similar body model of the user.

As discussed herein, the disclosed implementations may utilize one or more 2D partial body images and produce a full body model of the user represented in the 2D partial body images. The produced body model may include both a body model representation of visible segments of the body of the user represented in the image as well as segments of the body of the user that are not visible in the 2D body image.

The resulting dimensionally accurate body model of a body of a user may be utilized for a variety of purposes. For example, it may be presented to a user via an application executing on the same device as used to capture the 2D body images that were processed to generate the body model. With the application and the body model of the body of the user, the user can track changes to their body, determine body dimensions, measure portions of their body (e.g., arms, waist, shoulders, etc.), determine body mass, body volume, body fat, predict what they would look like if they gained muscle, lost fat, etc. In addition, with periodic updates using face images, the user can easily track progress at any time by providing a face image, rather than having to position an imaging element and generate a whole or partial body image of the body of the user.

FIG. 1A is a transition diagram 100 of processing 2D body images of a body to produce a dimensionally accurate body model of that body, in accordance with implementations of the present disclosure.

Modeling of a body from 2D body images begins with the receipt or creation of a 2D body image 102 that includes a representation of at least a portion of the body 103 of the user to be modeled. 2D body images 102 for use with the disclosed implementations may be generated using any conventional imaging element, such as a standard 2D Red, Green, Blue (“RGB”) digital camera that is included on many current portable devices (e.g., tablets, cellular phones, laptops, etc.). The 2D body image may be a still image generated by the imaging element or an image extracted from video generated by the imaging element. Likewise, any number of images may be used with the disclosed implementations.

In some implementations, the user may be instructed to stand in a particular orientation (e.g., front facing toward the imaging element, side facing toward the imaging element, back facing toward the imaging element, etc.) and/or to stand in a particular pose, such as the “A” pose as illustrated in image 102. Likewise, the user may be instructed to stand a distance from the camera such that the body of the user, or at least a portion thereof (such as the torso), is included in a field of view of the imaging element and represented in the generated image 102. Still further, in some implementations, the imaging element may be aligned or positioned at a fixed or stationary point and at a fixed or stationary angle so that images generated by the imaging element are each from the same perspective and encompass the same field of view. In the illustrated example, the user is positioned such that a lower portion of the body of the user is outside the field of view of the camera and therefore not represented in the image 102.

As will be appreciated, a user may elect or opt-in to having a body model of the body of the user generated and may also select whether the generated body model and/or other information may be used for further training of the disclosed implementations and/or for other purposes.

The 2D body image 102 that includes a representation of at least a portion of the body 103 of the user may then be processed to produce a segmented silhouette 104 of the body 103 of the user represented in the image 102. A variety of techniques may be used to generate the segmented silhouette 104. For example, background subtraction may be used to subtract or black out pixels of the image that correspond to a background of the image while pixels corresponding to the body 103 of the user (i.e., foreground) may be assigned a white or other color values. In another example, a semantic segmentation algorithm may be utilized to label background and body (foreground) pixels. For example, a convolutional neural network (“CNN”) may be trained with a semantic segmentation algorithm to determine bodies, such as human bodies, in images.

In addition or as an alternative thereto, the segmented silhouette may be segmented into one or more body segments, such as hair segment 104-1, head segment 104-2, neck segment 104-3, upper clothing segment 104-4, upper left arm 104-5, lower left arm 104-6, left hand 104-7, torso 104-8, upper right arm 104-9, lower right arm 104-10, right hand 104-11, lower clothing 104-12, upper left leg 104-13, upper right leg 104-16, etc. For example, the CNN may be trained with a semantic segmentation algorithm to predict for each pixel of an image the likelihood that the pixel corresponds to a segment label (e.g., hair, upper clothing, lower clothing, head, upper right arm, etc.). For example, the CNN may be trained to process each 2D body image and output, for each pixel of each image, a vector that indicates a probability for each label that the pixel corresponds to that label. For example, if there are twenty-three labels (e.g., body segments) for which the CNN is trained, the CNN may generate, for each pixel of a 2D image, a vector that includes a probability score for each of the twenty-three labels indicating the likelihood that the pixel corresponds to the respective label. As a result, each pixel of an image may be associated with a segment based on the probability scores indicated in the vector. For segments for which the CNN is trained but are not represented in the 2D image, the CNN will provide low or zero probability scores for each label indicated in the vector, thereby indicating that the segment is not visible in the 2D body image. As discussed, a segment may be determined by the CNN to not be visible if it is outside the view of the camera and therefore not represented in the 2D image or if another object is between the body segment and the camera such that the body segmented is occluded in the 2D image and therefore not visible. Likewise, for pixels that are determined to not correspond to one of the labels, those pixels may be labeled as background segments.

In some implementations, the segmented silhouette of the body of the user may be normalized in height and centered in the image, as discussed further below. This may be done to further simplify and standardize inputs to a CNN to those on which the CNN was trained. Likewise, a segmented silhouette of the body of the user may be preferred over the representation of the body of the user so that the CNN can focus only on body shape and each respective segment, and not skin tone, texture, clothing, etc.

The segmented silhouette 104 of the body may then be processed by one or more other CNNs 106 that are trained to determine body traits, also referred to herein as body features, representative of the body, determine if the entire body is represented in the image or if a portion of the body is outside the image or occluded by another object in the image, and to produce predicted body features that are used to generate a body model of the body. In some implementations, the CNN 106 may be trained for multi-mode input to receive as inputs to the CNN the segmented silhouette 104, and one or more known body attributes 105 of the body of the user. For example, a user may provide a height of the body of the user, a weight of the body of the user, a gender of the body of the user, etc., and the CNN may receive one or more of those provided attributes as an input.

In one example, based on the received inputs, a first CNN 106A generates predicted body features, such as body volume, shape of the body, pose angles, etc. Likewise, a second CNN 106B may receive the 2D body image 102 and/or the segmented silhouette 104 and determine 2D landmarks (e.g., x, y positions in the 2D body image) and/or visibility indicators for each 2D landmark of the body, indicating a likelihood that the 2D landmark is visible in the image (rather than beyond the image or occluded in the image by another object).

In some implementations, the CNN(s) 106 may be trained to predict hundreds of body features of the body represented in the image 102. For example, any number of 2D landmarks, such as top of head, ears, left shoulder, right shoulder, right elbow, left elbow, right wrist, left wrist, left hip, right hip, left knee, right knee, left ankle, right ankle, may be determined in accordance with the disclosed implementations. In such implementations, a visibility indicator may also be determined for each 2D landmark. The visibility indicator for each 2D landmark may be determined based on, for example, the position of the body segment(s) that connect to the 2D landmark, the position of other body segments and/or other 2D landmarks, etc. As discussed further below, because the CNN may generate data for each 2D landmark of the body, regardless of whether the 2D landmark is visible, the visibility indicator may be utilized with the disclosed implementations to improve the accuracy of body model rendering.

FIG. 1B is a transition diagram 120 of processing 2D face images to produce face-based body features that are used to update the body model generated as discussed with respect to FIG. 1A, in accordance with implementations of the present disclosure.

Generating face-based body features for updating an existing body model of a body begins with the receipt or creation of a 2D face image 122 that includes a representation of the face 123 of the user for which an existing body model has already been generated. 2D face images 122 for use with the disclosed implementations may be generated using any conventional imaging element, such as a standard 2D Red, Green, Blue (“RGB”) digital camera that is included on many current portable devices (e.g., tablets, cellular phones, laptops, etc.). The 2D body image may be a still image generated by the imaging element or an image extracted from video generated by the imaging element. Likewise, any number of images may be used with the disclosed implementations.

2D face images are generally easier for a user to generate. In some implementations, 2D face images may be obtained from any images of the user, such as “selfies,” also referred to herein as self-photos, images generated during a video call that includes the face of the user, intentional face photos captured by the user, etc. In other implementations, the user may be instructed to take a series of images or videos of the face of the user. For example, the user may be requested to generate a short video by moving a portable device from a left side view of the face of the user, to a front view of the face of the user, to a right side view of the face of the user.

The 2D face image 122 that includes a representation of the face 123 of the user may then be processed to produce a silhouette 124 of the face 123 of the user represented in the image 122. As discussed above, a variety of techniques may be used to generate the silhouette 124. For example, background subtraction may be used to subtract or black out pixels of the image that correspond to a background of the image while pixels corresponding to the face 123 of user (i.e., foreground) may be assigned a white or other color values. In another example, a semantic segmentation algorithm may be utilized to label background and face (foreground) pixels. For example, a CNN may be trained with a semantic segmentation algorithm to determine faces, such as human faces, in images. In other implementations, other techniques may be utilized in addition to or instead of determining a silhouette.

The silhouette 124 of the face may then be processed by one or more other CNNs 126 that are trained to determine body traits, also referred to herein as body features, representative of the body based only on a face image and to produce face-based predicted body features. In such an example, the face image does not represent any portion of the body other than the face of the body. In some implementations, the CNN 126 may be trained for multi-mode input to receive as inputs to the CNN the silhouette 124, and one or more known body attributes 105 of the body of the user. For example, a user may provide a height of the body of the user, a weight of the body of the user, a gender of the body of the user, etc., and the CNN may receive one or more of those provided attributes as an input.

In some implementations, the CNN 126 may be trained using both face images and body images such that the CNN 126 is trained to predict body features determined from the body images using only the face images. In other implementations, the CNN 126 may be the same CNN discussed above with respect to FIG. 1A. In such an example, the CNN 126 may be informed that the only segment that is visible is the face or head segment. In still other examples, the CNN 126 may be trained to predict body features based only face images utilized as training inputs.

Based on the received inputs, the CNN 126 generates face-based predicted body features, such as body volume, shape of the body, etc. In some implementations, the CNN 126 may hallucinate joint locations of the entire body, taking into consideration the known joint locations determined from the body model generation discussed herein. The CNN 126 may be trained to predict hundreds of face-based body features of the body corresponding to the face represented in the image 122.

Utilizing the face-based predicted body features, the existing body model 129 of the body, generated as discussed above, may be updated 128 with the face-based body features. For example, the face-based body features and the body features of the existing body model of the body may be provided to a body model, such as the Shape Completion and Animation of People (“SCAPE”) body model, a Skinned Multi-Person Linear (“SMPL”) body model, etc., and the body model may update the body model of the body of the user based on those face-based predicted body features.

As discussed further below, in some implementations, it may be determined whether the difference between the face-based body features and the body features determined for the body based on a 2D body image exceed a threshold. If the difference exceeds the threshold, the update of the body model may not be performed based on the face-based body features and the user may be requested to provide 2D body images so that the body model can be regenerated/updated based on the new 2D body images.

Still further, in some implementations, the updated body model 130 of the body of the user may be augmented with one or more textures, texture augmentation 132, determined from the face 123 of the user. For example, the body model may be updated based on the skin color determined from the face 123 of the user represented in the image 122. In other examples, details of the face, such as facial features, hair, hair color, etc., of the body of the user represented in the face image 122 may be determined and used to augment the body model, etc.

The result of the processing illustrated in the transition 120 is a dimensionally accurate body model 134 or avatar representative of the body of the user, that has been generated from 2D body images of the body of the user and subsequently updated based on 2D face images of the face of the user.

FIG. 1C is a diagram of an image 104 of a body of a user with 2D landmarks 151 indicated both inside and outside of the image, in accordance with implementations of the present disclosure.

As discussed, the 2D body image or segmented silhouette of the 2D body image may be processed to determine 2D landmarks 151 of the body. For example, the image 104 may be provided to a trained machine learning model, such as a CNN that is trained to determine 2D landmarks of a body represented in an image. Based on the provided input, the CNN may generate an output indicating the location (e.g., x, y coordinates, or pixels) corresponding to the 2D landmarks for which the CNN was trained. In the illustrated example, the CNN may indicate 2D landmarks for the top of head 151-1, left ear 151-2, left shoulder 151-3, left elbow 151-4, left wrist 151-5, left hip 151-6, left knee 151-7, right ear 151-10, neck 151-11, right shoulder 151-12, right elbow 151-13, right wrist 151-14, right hip 151-15, and right knee 151-16, all of which are visible in the image 154. Likewise, in some implementations, the CNN may also infer the location of 2D landmarks that are not visible in the image 154, such as the left ankle 151-8, left foot 151-9, right ankle 151-17, and right foot 151-18. Such inference may not only indicate the inferred location of the 2D landmarks that are not visible but also indicate, such as through a visibility indicator, that the inferred positions of the 2D landmarks are determined to not be visible in the input image 104. Likewise, in some implementations, the CNN may provide a visibility indicator for 2D landmarks that are determined to be visible in the input image indicating that the 2D landmarks are visible.

Utilizing the predicted body features and visibility indicators, a body model of the body is generated. For example, the body features may be provided to a body model, such as the Shape Completion and Animation of People (“SCAPE”) body model, a Skinned Multi-Person Linear (“SMPL”) body model, etc., and the body model may generate the body model of the body of the user based on those predicted body features. To improve accuracy of the body model, in some implementations, data corresponding to any 2D landmark that is determined to not be visible, as indicated by the respective visibility indicator, may be ignored or omitted by the body model in generation of the body model as the data for those landmark body features may be unreliable or inaccurate. Instead, the model may determine 2D landmarks for those non-visible body joints based on the position of other body joints of the body of the user that are visible. In other implementations, the inferred position for one or more 2D landmarks that are determined to not be visible, such as those that are within the field of view of the image but occluded, may be considered in determining the body model.

In some implementations, as discussed further below, body model refinement 108 may be performed to refine or revise the generated body model to better represent the body of the user. Initially, for each 2D landmark determined to be visible in the image, as indicated by the corresponding visibility indicator, the position of the 2D landmark as represented in the body model may be compared with the representation of the body 103 of the user in the 2D image 102 to determine differences therebetween. The determined 2D landmarks may be updated to align the determined 2D landmarks that are used to generate the body model with the position of those 2D landmarks as represented in the 2D body image 102.

In addition to aligning the 2D landmarks, body model refinement 108 may process each body segment of the body model with respect to the corresponding segment as specified in the segmented silhouette. For example, each body segment of the body model may be compared with each segment of the segmented silhouette. An error or difference between each body segment comparison may be determined and one or more of the body segments as represented in the body model may be adjusted to correct for the error. The adjustments and comparisons may be done in an iterative fashion until there is no or little difference between the shape of the body 103 of the user represented in the image 102 and the shape of the body model 110. For example, the segmented silhouette and the body model may be provided to a machine learning system, such as PYTORCH, and the body segments of the body model may be adjusted based on an iterative comparison of each body segment of the body model with the body segments of the segmented silhouette. For body segments that are not visible, the body segment size, shape, and position may be generated or determined based on the position of other body segments and/or 2D landmarks of the body that are visible in the 2D image from which the body model was generated. Likewise, those body segments may be adjusted or updated as part of the iterative processing and refinement of the visible body segments.

Still further, in some implementations, the body model 110 of the body of the user may be augmented with one or more textures, texture augmentation 112, determined from the image 102 of the body of the user. For example, the body model may be augmented to have a same or similar color to a skin color of the body 103 represented in the image 102, clothing or clothing colors represented in the image 102 may be used to augment the body model, facial features, hair, hair color, etc., of the body of the user represented in the image 102 may be determined and used to augment the body model, etc. As discussed below, for body segments that are not visible, as indicated by the visibility indicator, the texture may be predicted based on textures of adjacent body segments and applied to the body model.

The result of the processing illustrated in the transition 100 is a dimensionally accurate body model 114, or avatar representative of the body of the user, that has been generated from 2D body images of the body of the user. As discussed herein, some or all of the portions of the 2D body that are not visible in the 2D images may be generated and included in the body model.

FIG. 2A is another transition diagram 200 of processing 2D body images 202 of a body to produce a dimensionally accurate three-dimensional model of that body, in accordance with implementations of the present disclosure.

In some implementations, multiple 2D body images of at least a portion of a body from different views (e.g., front view, side view, back view, three-quarter view, etc.), such as 2D body images 202-1, 202-2, 202-3, 202-4 through 202-N may be utilized with the disclosed implementations to generate a dimensionally accurate body model of the body. In the illustrated example, the first 2D body image 202-1 is an image of at least a portion of a human body 203 oriented in a front view facing a 2D imaging element. The second 2D body image 202-2 is an image of at least a portion of the human body 203 oriented in a first side view facing the 2D imaging element. The third 2D body image 202-3 is an image of at least a portion of the human body 203 oriented in a back view facing the 2D imaging element. The fourth 2D body image 202-4 is an image of at least a portion of the human body 203 oriented in a second side view facing the 2D imaging element. As will be appreciated, any number of 2D body images 202-1 through 202-N may be generated with the view of at least a portion of the human body 203 in any number of orientations with respect to the 2D imaging element. In some implementations, some of the 2D body images may be 2D partial body images while other 2D body images include a full representation of the body of the user.

Each of the 2D body images 202-1 through 202-N are processed to segment pixels of the image to different body segments (or to background) to produce a segmented silhouette 204 of the human body as represented in that image. Segmentation may be done as discussed above with respect to FIG. 1A. For example, a CNN utilizing a semantic segmentation algorithm may be trained using images of human bodies, or simulated human bodies, to train the CNN to distinguish between pixels that represent different body segments of human bodies. In such an example, the CNN may process the image 202 and indicate or label pixels that represent different body segments (head, hair, upper right arm, lower left leg, etc.), as well as pixels that do not represent a human body part, such as background or other objects represented in the image. Each pixel may be assigned a vector that indicates a probability score for each label as to whether the pixel corresponds to the labeled body segment.

In other implementations, other forms or algorithms, such as edge detection, shape detection, etc., may be used to determine pixels of the image 202 that represent different body segments of the user.

Returning to FIG. 2A, the first 2D body image 202-1 is processed to segment a plurality of pixels of the first 2D body image 202-1 into different body segments, to produce a front segmented silhouette 204-1 of the human body. The second 2D body image 202-2 is processed to segment a plurality of pixels of the second 2D body image 202-2 into different body segments, to produce a first side segmented silhouette 204-2 of the human body. The third 2D body image 202-3 is processed to segment a plurality of pixels of the third 2D body image 202-3 into different body segments, to produce a back segmented silhouette 204-3 of the human body. The fourth 2D body image 202-4 is processed to segment a plurality of pixels of the fourth 2D body image 202-4 into different body segments, to produce a second side segmented silhouette 204-4 of the human body. Processing of the 2D body images 202-1 through 202-N to produce segmented silhouettes 204-1 through 204-N from different orientations of the human body 203 may be performed for any number of images 202.

In some implementations, in addition to generating a segmented silhouette 204 from the 2D body image, the segmented silhouette may be normalized in size and centered in the image. For example, the segmented silhouette may be cropped by computing a bounding rectangle around the segmented silhouette 204. The segmented silhouette 204 may then be resized according to s, which is a function of a known height h of the user represented in the 2D body image (e.g., the height may be provided by the user):

$\begin{matrix} {s = {h*\frac{0.8*{image}_{h}}{\mu_{h}}}} & (1) \end{matrix}$ Where image_(h), is the input image height, which may be based on the pixels of the image, and μ_(h) is the average height of a person (e.g., ˜160 centimeters for females; ˜176 centimeters for males).

In addition to processing the 2D body images 202 to generate body segments, the 2D body images may be processed to determine visibility indicators for one or more 2D landmarks of the body. For example, the first 2D body image 202-1 may be processed by a first visibility indicator CNN 206B-1 to determine visibility indicators for each of one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the first 2D body image 202-1. The second 2D body image 202-2 may be processed by a second visibility indicator CNN 206B-2 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the second 2D body image 202-2. The third 2D body image 202-3 may be processed by a third visibility indicator CNN 206B-3 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the third 2D body image 202-3. The fourth 2D body image 202-4 may be processed by a fourth visibility indicator CNN 206B-4 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the fourth 2D body image 202-4. Processing of the 2D body images may be done for each image, through the Nth 2D body image 202-N, which may be processed by an Nth visibility indicator CNN 206B-N to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the Nth 2D body image 202-N. While the illustrated example describes each 2D body image being processed by a separate neural network to determine respective visibility indicators, in other implementations, one or more of the 2D body images 202 may be processed by the same neural network (e.g., the same CNN). The visibility indicators for each of the one or more 2D landmarks, generated by each of the visibility indicators CNNs 206B, may be provided to body modeling 210.

Each segmented silhouette 204 representative of the body may also be processed to determine body traits or features of the human body. Different CNNs may be trained using segmented silhouettes of bodies, such as human bodies, from different orientations with known features. In some implementations, different CNNs may be trained for different orientations. For example, a first CNN 206A-1 may be trained to determine front view features from front view segmented silhouettes 204-1. A second CNN 206A-2 may be trained to determine right side features from right side segmented silhouettes. A third CNN 206A-3 may be trained to determine back view features from back view segmented silhouettes. A fourth CNN 206A-4 may be trained to determine left side features from left side segmented silhouettes. Different CNNs 206A-1 through 206A-N may be trained for each of the different orientations of segmented silhouettes 204-1 through 204-N. Alternatively, one CNN may be trained to determine features from any orientation segmented silhouette. Likewise, CNNs may be trained based on both 2D partial body images and full 2D body images and/or partial segmented silhouettes and full segmented silhouettes. In some implementations, the same CNN may be used to determine body features and visibility indicators for one or more of the 2D body images.

In implementations that utilize multiple images of the body 203 to produce multiple sets of features, such as the example illustrated in FIG. 2A, those features may be concatenated 206C and the concatenated features processed together with a CNN to generate a set of predicted body features 207. For example, a CNN may be trained to receive features generated from different segmented silhouettes 204 to produce predicted body features 207. The predicted body features 207 may indicate any aspect or information related to the body 203 represented in the images 202. For example, the predicted body features 207 may indicate body volume, shape of the body, pose angles, etc. In some implementations, the CNN 206C may be trained to predict hundreds of body features 207 corresponding to the body 203 represented in the images 202.

Utilizing the predicted body features 207 and visibility indicators received from the one or more visibility indicator CNNs 206B, body modeling 210 of the body 203 represented in the 2D body images 202 is performed to generate a body model of the body 203 represented in the 2D body images 202. As illustrated above, the body model may be a full representation of the body of the user, even if the 2D body images are 2D partial body images. For example, if the input images do not include a representation of the lower leg segments and feet of the user, such as the example discussed above, the generated body model may include a model of the non-visible segments of the body of the user, in this example the lower leg segments and feet.

The body features 207 may be provided to a body model, such as the SCAPE body model, the SMPL body model, etc., and the body model may generate the body model of the body 203 represented in the images 202 based on those predicted body features 207. To improve accuracy of the body model, in some implementations, data corresponding to any 2D landmark that is determined to not be visible, as indicated by the respective visibility indicator, may be ignored or omitted by the body model in generation of the body model as the data for those landmark body features may be unreliable or inaccurate. Instead, the model may determine 2D landmarks for those non-visible body joints based on the position of other body joints of the body of the user that are visible.

In the illustrated example, body model refinement 208 may be performed to refine or revise the generated body model to better represent the body 203 represented in the 2D body images 202. Initially, for each 2D landmark determined to be visible in one or more of the images 202, as indicated by the corresponding visibility indicator, the position of the 2D landmark as represented in the body model may be compared with the representation of the body of the user in the 2D image 202 to determine differences therebetween. The determined 2D landmarks may then be updated to align the determined 2D landmarks that are used to generate the body model with the position of those 2D landmarks as represented in the 2D body image 202.

In addition to aligning the 2D landmarks, body model refinement 208 may process each body segment of the body model with respect to the corresponding segment as specified in the segmented silhouette. For example, each body segment of the body model may be compared with each segment of the segmented silhouette. An error or difference between each body segment comparison may be determined and one or more of the body segments as represented in the body model may be adjusted to correct for the error. The adjustments and comparisons may be done in an iterative fashion until there is no or little difference between the shape of the body 203 of the user represented in the image 202 and the shape of the body model. For example, the segmented silhouette and the body model may be provided to a machine learning system, such as PYTORCH, and the body segments of the body model may be adjusted based on an iterative comparison of each body segment of the body model with the visible body segments of the segmented silhouette. For body segments that are not visible, the body segment size, shape, and position may be generated or determined based on the position of other body segments and/or 2D landmarks of the body that are visible in the 2D image from which the body model was generated. Likewise, those body segments may be adjusted or updated as part of the iterative processing and refinement of the visible body segments.

In some implementations, the body model may be compared to a single image, such as image 202-1. In other implementations, the body model may be compared to each of the 2D body images 202-1 through 202-N in parallel or sequentially. In still other implementations, one or more 2D model images may be generated from the body model and those 2D model images may be compared to the segmented silhouettes and/or the 2D body images to determine differences between the 2D model images and the segmented silhouette/2D body images.

Comparing the body model and/or a 2D model image with a 2D body image 202 or segmented silhouette 204 may include determining an approximate pose of the body 203 represented in the 2D body image and adjusting the body model to the approximate pose. The body model or rendered 2D model image may then be overlaid or otherwise compared to the body 203 represented in the 2D body image 202 and/or represented in the segmented silhouette 204 to determine a difference between body segments of the body model and visible body segments of the 2D body image.

Based on the determined differences between the body model and the body 203 represented in the 2D body image 202, the segmented silhouette 204 generated from that image may be revised to account for those differences. For example, if body segments of the body model are compared with the visible body segments determined for the body 203 represented in the first image 202-1 and differences are determined, the segmented silhouette 204-1 may be revised based on those differences. Alternatively, the predicted body features and/or the body model may be revised to account for those differences.

If body segments of a segmented silhouette are revised as part of the body model refinement 208, the revised segmented silhouette may be processed to determine revised features for the body 203 represented in the 2D body image based on the revised segmented silhouette. The revised features may then be concatenated with the features generated from the other segmented silhouettes or with revised features generated from other revised segmented silhouettes that were produced by the body model refinement 208. For example, the body model refinement 208 may compare body segments of the generated body model with visible body segments of the body 203 as represented in two or more 2D body images 202, such as a front image 202-1 and a back image 202-3, differences determined for each of those images, revised segmented silhouettes generated from those differences and revised front view features and revised back view features generated. Those revised features may then be concatenated with the two side view features to produce revised predicted body model features. In other implementations, body model refinement 208 may compare the body model with all views of the body 203 represented in the 2D body images 202 to determine differences and generate revised segmented silhouettes for each of those 2D body images 202-1 through 202-N. Those revised segmented silhouettes may then be processed by the CNNs 206A-1 through 206A-N to produce revised features and those revised features concatenated to produce revised predicted body features 207. Finally, the revised predicted body features may be processed by body modeling 210 to generate a revised body model, with respective revised body segments. This process of body refinement may continue until there is no or limited difference (e.g., below a threshold difference) between the body segments of the generated body model and the visible body segments of the body 203 represented in the 2D body images 202.

In another implementation, body model refinement 208 may sequentially compare body segments of the body model with visible body segments determined for the representations of the body 203 in the different 2D body images 202. For example, body model refinement 208 may compare body segments of the body model with visible body segments determined for a first representation of the body 203 in a first 2D body image 202-1 to determine differences that are then used to generate a revised segmented silhouette 204-1 corresponding to that first 2D body image 202-1. The revised segmented silhouette may then be processed to produce revised features and those revised features may be concatenated 206C with the features generated from the other segmented silhouettes 204-2 through 204-N to generate revised predicted body features, which may be used to generate a revised body model. The revised body segments of the revised body model may then be compared with visible body segments of a next image of the plurality of 2D body images 202 to determine any differences and the process repeated. This process of body segment refinement may continue until there is no or limited difference (e.g., below a threshold difference) between the body segments of the generated body model and the visible body segments of the body 203 represented in the 2D body images 202.

In some implementations, upon completion of body model refinement 208, the body model of the body represented in the 2D body images 202 may be augmented with one or more textures, texture augmentation 212, determined from one or more of the 2D body images 202-1 through 202-N. For example, the body model may be augmented to have a same or similar color to a skin color of the body 203 represented the 2D body images 202, clothing or clothing colors represented in the 2D body images 202 may be used to augment the body model, facial features, hair, hair color, etc., of the body 203 represented in the 2D body image 202 may be determined and used to augment the body model. For body segments of the body model that are not visible in the 2D body images, the texture for those segments may be predicted from other segments of the body model. Likewise, in some implementations, clothing segments, such as upper clothing and lower clothing may be aligned with corresponding body segments or 2D landmarks of the body model to ensure that the representation of the clothes are aligned with the proper body segment of the body model.

Similar to body model refinement, the approximate pose of the body in one of the 2D body images 202 may be determined and the body model adjusted accordingly so that the texture obtained from that 2D body image 202 may be aligned and used to augment that portion of the body model. In some implementations, alignment of the body model with the approximate pose of the body 203 may be performed for each 2D body image 202-1 through 202-N so that texture information or data from the different views of the body 203 represented in the different 2D body images 202 may be used to augment the different poses of the resulting body model.

The result of the processing illustrated in the transition 200 is a dimensionally accurate body model 214 or avatar representative of the body of the user, that has been generated from 2D body images 202 of the body 203 of the user, regardless of whether all or only a portion of the body was represented and visible in the 2D body image(s). In some implementations, the resulting model may be cropped to exclude aspects of the model from any rendering that is presented to the user. For example, in some implementations, the body model may be cropped to represent the body model from the neck to the ankles, excluding the head and feet. In other implementations, all of the body model may be rendered and presented.

FIG. 2B is another transition diagram 250 of processing 2D body images 252 of a body to produce a dimensionally accurate three-dimensional model of that body, in accordance with implementations of the present disclosure.

In some implementations, multiple 2D body images of a body from different views (e.g., front view, side view, back view, three-quarter view, etc.), such as 2D body images 252-1, 252-2, 252-3, 252-4 through 252-N may be utilized with the disclosed implementations to generate a dimensionally accurate body model of the body. In the illustrated example, the first 2D body image 252-1 is an image of at least a portion of a human body 253 oriented in a front view facing a 2D imaging element. The second 2D body image 252-2 is an image of at least a portion of the human body 253 oriented in a first side view facing the 2D imaging element. The third 2D body image 252-3 is an image of at least a portion of the human body 253 oriented in a back view facing the 2D imaging element. The fourth 2D body image 252-4 is an image of at least a portion of the human body 253 oriented in a second side view facing the 2D imaging element. As will be appreciated, any number of 2D body images 252-1 through 252-N may be generated with the view of the human body 253 in any number of orientations with respect to the 2D imaging element. In some implementations, some of the 2D body images may be 2D partial body images while other 2D body images include a full representation of the body of the user.

Each of the 2D body images 252-1 through 252-N are processed to segment pixels of the image to different body segments (or to background) to produce a segmented silhouette 254 of the human body as represented in that image. Segmentation may be done as discussed above with respect to FIG. 1A. For example, a CNN utilizing a semantic segmentation algorithm may be trained using images of human bodies, or simulated human bodies to train the CNN to distinguish between pixels that represent different body segments of human bodies. In such an example, the CNN may process the image 252 and indicate or label pixels that represent different body segments (head, hair, upper right arm, lower left leg, etc.), as well as pixels that do not represent a human body part, such as background or other objects represented in the image. Each pixel may be assigned a vector that indicates a probability score for each label as to whether the pixel corresponds to the labeled body segment.

In other implementations, other forms or algorithms, such as edge detection, shape detection, etc., maybe used to determine pixels of the image 252 that represent different body segments of the user.

Returning to FIG. 2B, the first 2D body image 252-1 is processed to segment a plurality of pixels of the first 2D body image 252-1 into different body segments, to produce a front segmented silhouette 254-1 of the human body. The second 2D body image 252-2 is processed to segment a plurality of pixels of the second 2D body image 252-2 into different body segments, to produce a first side segmented silhouette 254-2 of the human body. The third 2D body image 252-3 is processed to segment a plurality of pixels of the third 2D body image 252-3 into different body segments, to produce a back segmented silhouette 254-3 of the human body. The fourth 2D body image 252-4 is processed to segment a plurality of pixels of the fourth 2D body image 252-4 into different body segments, to produce a second side segmented silhouette 254-4 of the human body. Processing of the 2D body images 252-1 through 252-N to produce segmented silhouettes 254-1 through 254-N from different orientations of the human body 253 may be performed for any number of images 252.

Similar to FIG. 2A, in some implementations, in addition to generating a segmented silhouette 254 from the 2D body image, the segmented silhouette may be normalized in size and centered in the image. For example, the segmented silhouette may be cropped by computing a bounding rectangle around the segmented silhouette 254. The segmented silhouette 254 may then be resized according to s, described above with respect to equation (1). In some implementations, the body 253 represented in the 2D body image may be similarly resized to correspond to the resized dimensions of the resized segmented silhouette.

In addition to processing the 2D body images 252 to generate body segments, the 2D body images may be processed to determine visibility indicators for one or more 2D landmarks of the body. For example, the first 2D body image 252-1 may be processed by a first visibility indicator CNN 256B-1 to determine visibility indicators for each of one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the first 2D body image 252-1. The second 2D body image 252-2 may be processed by a second visibility indicator CNN 256B-2 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the second 2D body image 252-2. The third 2D body image 252-3 may be processed by a third visibility indicator CNN 256B-3 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the third 2D body image 252-3. The fourth 2D body image 252-4 may be processed by a fourth visibility indicator CNN 256B-4 to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the fourth 2D body image 252-4. Processing of the 2D body images may be done for each image, through the Nth 2D body image 252-N, which may be processed by an Nth visibility indicator CNN 256B-N to determine visibility indicators for each of the one or more 2D landmarks, each visibility indicator indicating whether the respective landmark is visible in the Nth 2D body image 252-N. While the illustrated example describes each 2D body image being processed by a separate neural network to determine respective visibility indicators, in other implementations, one or more of the 2D body images 252 may be processed by the same neural network (e.g., the same CNN). The visibility indicators for each of the one or more 2D landmarks, generated by each of the visibility indicators CNNs 256B may be provided to body modeling 260.

Each segmented silhouette 254 representative of the body may then be processed to determine body traits or features of the human body. For example, different CNNs may be trained using segmented silhouettes of bodies, such as human bodies, from different orientations with known features. In some implementations, different CNNs may be trained for different orientations. For example, a first CNN 256A-1 may be trained to determine front view features from front view segmented silhouettes 254-1. A second CNN 256A-2 may be trained to determine right side features from right side segmented silhouettes. A third CNN 256A-3 may be trained to determine back view features from back view segmented silhouettes. A fourth CNN 256A-4 may be trained to determine left side features from left side segmented silhouettes. Different CNNs 256A-1 through 256A-N may be trained for each of the different orientations of segmented silhouettes 254-1 through 254-N. Alternatively, one CNN may be trained to determine features from any orientation segmented silhouette. Likewise, the same CNN may be used to determine body features and visibility indicators of one or more of the 2D body images.

In some implementations, the same or different CNNs may also utilize the 2D body image 202 as an input to the CNN that is used to generate and determine the body features. For example, the first CNN 256A-1 may be trained to determine front view features based on inputs of the front view segmented silhouettes 254-1 and/or the 2D body image 252-1. The second CNN 256A-2 may be trained to determine right side features from right side segmented silhouettes and/or the right side 2D body image 252-2. The third CNN 256A-3 may be trained to determine back view features from back view segmented silhouettes and/or the back view 2D body image 252-3. The fourth CNN 256A-4 may be trained to determine left side features from left side segmented silhouettes and/or the left side 2D body image 252-4. Different CNNs 256A-1 through 256A-N may be trained for each of the different orientations of segmented silhouettes 254-1 through 254-N and/or 2D body images 252-1 through 252-N.

In still other implementations, different CNNS may be trained for each of the segmented silhouettes 254 and the 2D body images. For example, the first CNN 256A-1 may be trained to determine front view features from the segmented silhouette 254-1 and another front view CNN may be trained to determine front view features from the 2D body image 252-1. The second CNN 256A-2 may be trained to determine right side view features from the segmented silhouette 254-2 and another right side view CNN may be trained to determine right side view features from the 2D body image 252-2. The third CNN 256A-3 may be trained to determine back view features from the segmented silhouette 254-3 and another back view CNN may be trained to determine back view features from the 2D body image 252-3. The fourth CNN 256A-4 may be trained to determine left side view features from the segmented silhouette 254-4 and another left side view CNN may be trained to determine left side view features from the 2D body image 252-4.

In implementations that utilize multiple images of the body 253 and/or multiple segmented silhouettes to produce multiple sets of features, such as the example illustrated in FIG. 2B, those features may be concatenated 256C and the concatenated features processed together with a CNN to generate a set of predicted body features 257. For example, a CNN may be trained to receive features generated from different segmented silhouettes 254, features generated from different 2D body images 252, and/or features generated by a CNN that processes both segmented silhouettes 254 and the 2D body images 252 to produce predicted body features 257. The predicted body features 257 may indicate any aspect or information related to the body 253 represented in the images 252. For example, the predicted body features 257 may indicate body volume, shape of the body, pose angles, etc. In some implementations, the CNN 256C may be trained to predict hundreds of body features 257 corresponding to the body 253 represented in the images 252.

Utilizing the predicted body features 257 and visibility indicators 256 received from the one or more visibility indicator CNNs 256B, body modeling 260 of the body 253 represented in the 2D body images 252 is performed to generate a body model of the body 253 represented in the 2D body images 252. As illustrated above, the body model may be a full representation of the body of the user, even if the 2D body images are 2D partial body images. For example, if the input images do not include a representation of the lower leg segments and feet of the user, such as the example discussed above, the generated body model may include a model of the non-visible segments of the body of the user, in this example the lower leg segments and feet.

The body features 257 may be provided to a body model, such as the SCAPE body model, the SMPL body model, etc., and the body model may generate the body model of the body 253 represented in the images 252 based on those predicted body features 257. To improve accuracy of the body model, in some implementations, data corresponding to any 2D landmark that is determined to not be visible, as indicated by the respective visibility indicator, may be ignored or omitted by the body model in generation of the body model as the data for those landmark body features may be unreliable or inaccurate. Instead, the model may determine 2D landmarks for those non-visible body joints based on the position of other body joints of the body of the user that are visible.

In the illustrated example, body model refinement 258 may be performed to refine or revise the generated body model to better represent the body 253 represented in the 2D body images 252. Initially, for each 2D landmark determined to be visible in one or more of the images 252, as indicated by the corresponding visibility indicator, the position of the 2D landmark as represented in the body model may be compared with the representation of the body of the user in the 2D image 252 to determine differences therebetween. The determined 2D landmarks may then be updated to align the determined 2D landmarks that are used to generate the body model with the position of those 2D landmarks as represented in the 2D body image 252.

In addition to aligning the 2D landmarks, body model refinement 258 may process each body segment of the body model with respect to the corresponding segment as specified in the segmented silhouette. For example, each body segment of the body model may be compared with each segment of the segmented silhouette. An error or difference between each body segment comparison may be determined and one or more of the body segments as represented in the body model may be adjusted to correct for the error. The adjustments and comparisons may be done in an iterative fashion until there is no or little difference between the shape of the body 253 of the user represented in the image 252 and the shape of the body model. For example, the segmented silhouette and the body model may be provided to a machine learning system, such as PYTORCH, and the body segments of the body model may be adjusted based on an iterative comparison of each body segment of the body model with the visible body segments of the segmented silhouette. For body segments that are not visible, the body segment size, shape, and position may be generated or determined based on the position of other body segments and/or 2D landmarks of the body that are visible in the 2D image from which the body model was generated. Likewise, those body segments may be adjusted or updated as part of the iterative processing and refinement of the visible body segments.

In some implementations, the body model may be compared to a single image, such as image 252-1. In other implementations, the body model may be compared to each of the 2D body images 252-1 through 252-N in parallel or sequentially. In still other implementations, one or more 2D model images may be generated from the body model and those 2D model images may be compared to the segmented silhouettes and/or the 2D body images to determine differences between the 2D model images and the segmented silhouette/2D body images.

Comparing the body model and/or a 2D model image with a 2D body image 252 or segmented silhouette 254 may include determining an approximate pose of the body 253 represented in the 2D body image and adjusting the body model to the approximate pose. The body model or rendered 2D model image may then be overlaid or otherwise compared to the body 253 represented in the 2D body image 252 and/or represented in the segmented silhouette 254 to determine a difference between body segments of the body model and visible body segments of the 2D body image.

Based on the determined differences between the body model and the body 253 represented in the 2D body image 252, the segmented silhouette 254 generated from that image may be revised to account for those differences. Alternatively, the predicted body features and/or the body model may be revised to account for those differences.

In some implementations, upon completion of body model refinement 258, the body model of the body represented in the 2D body images 252 may be augmented with one or more textures, texture augmentation 262, determined from one or more of the 2D body images 252-1 through 252-N. For example, the body model may be augmented to have a same or similar color to a skin color of the body 253 represented in the 2D body images 252, clothing or clothing colors represented in the 2D body images 252 may be used to augment the body model, facial features, hair, hair color, etc., of the body 253 represented in the 2D body image 252 may be determined and used to augment the body model. For body segments of the body model that are not visible in the 2D body images, the texture for those segments may be predicted from other segments of the body model. Likewise, in some implementations, clothing segments, such as upper clothing and lower clothing may be aligned with corresponding body segments or 2D landmarks of the body model to ensure that the representation of the clothes are aligned with the proper body segment of the body model.

Similar to body model refinement, the approximate pose of the body in one of the 2D body images 252 may be determined and the body model adjusted accordingly so that the texture obtained from that 2D body image 252 may be aligned and used to augment that portion of the body model. In some implementations, alignment of the body model with the approximate pose of the body 253 may be performed for each 2D body image 252-1 through 252-N so that texture information or data from the different views of the body 253 represented in the different 2D body images 252 may be used to augment the different poses of the resulting body model.

The result of the processing illustrated in the transition 250 is a dimensionally accurate body model 264, or avatar representative of the body of the user, that has been generated from 2D body images 252 of the body 253 of the user, regardless of whether all or only a portion of the body was represented and visible in the 2D body image(s). In some implementations, the resulting model may be cropped to exclude aspects of the model from any rendering that is presented to the user. For example, in some implementations, the body model may be cropped to represent the body model from the neck to the ankles, excluding the head and feet. In other implementations, all of the body model may be rendered and presented.

FIG. 2C is another transition diagram 270 of processing 2D face images 272 of a face to produce faced-based predicted body features that are used to update an existing body model of a body, in accordance with implementations of the present disclosure.

In some implementations, multiple 2D face images of a face of a body from different views (e.g., front view, left side view, ride side view, three-quarter view, etc.), such as 2D face images 272-1, 272-2, 272-3, through 272-N may be utilized with the disclosed implementations to generate face-based predicted body features for a body for which an existing body model of the body already exists. In the illustrated example, the first 2D face image 272-1 is an image of a human face 273 oriented in a front view facing a 2D imaging element. The second 2D face image 272-2 is an image of the face 273 of the human body oriented in a first side view facing the 2D imaging element. The third 2D body image 272-3 is an image of the face 273 of the human body oriented in a second side view facing the 2D imaging element. As will be appreciated, any number of 2D face images 272-1 through 272 -N may be generated with the view of the face 273 of the human body in any number or orientations with respect to the 2D imaging element.

Each of the 2D face images 272-1 through 272-N are processed to segment pixels of the image that represent the face of the human body from pixels of the image that do not represent the face of the human body to produce a silhouette 274 of the face as represented in that image. Segmentation may be done through, for example, background subtraction, semantic segmentation, etc. In one example, a baseline image of the background may be known and used to subtract out pixels of the image that correspond to pixels of the baseline image, thereby leaving only foreground pixels that represent the face. The background pixels may be assigned RGB color values for black (i.e., 0,0,0). The remaining pixels may be assigned RGB values for white (i.e., 255, 255, 255) to produce the silhouette 274 or binary segmentation of the face of the human body.

In another example, a CNN utilizing a semantic segmentation algorithm may be trained using images of faces of human bodies, alone or in combination with image(s) of the corresponding human body, and/or simulated faces of human bodies, to train the CNN to distinguish between pixels that represent faces of human bodies and pixels that do not represent faces of human bodies. In such an example, the CNN may process the image 272 and indicate or label pixels that represent the face (foreground) and pixels that do not represent the face (background). The background pixels may be assigned RGB color values for black (i.e., 0,0,0). The remaining pixels may be assigned RGB values for white (i.e., 255, 255, 255) to produce the silhouette or binary segmentation of the face of the human body.

In other implementations, other forms or algorithms, such as edge detection, shape detection, etc., may be used to determine pixels of the image 272 that represent the face and pixels of the image 272 that do not represent the face and a silhouette 274 of the face of the body produced therefrom.

Returning to FIG. 2C, the first 2D face image 272-1 is processed to segment a plurality of pixels of the first 2D face image 272-1 that represent the face of the human body from a plurality of pixels of the first 2D face image 272-1 that do not represent the face of the human body, to produce a front silhouette 274-1 of the face of the human body. The second 2D face image 272-2 is processed to segment a plurality of pixels of the second 2D face image 272-2 that represent the face of the human body from a plurality of pixels of the second 2D face image 272-2 that do not represent the face of the human body, to produce a first side silhouette 274-2 of the face of the human body. The third 2D face image 272-3 is processed to segment a plurality of pixels of the third 2D face image 272-3 that represent the face of the human body from a plurality of pixels of the third 2D face image 272-3 that do not represent the face of the human body, to produce a second side silhouette 274-3 of the face of the human body. Processing of the 2D face images 272-1 through 272-N to produce silhouettes 274-1 through 274-N from different orientations of the face of the human body 273 may be performed for any number of images 272.

In some implementations, in addition to generating a silhouette 274 from the 2D face image, the silhouette may be normalized in size and centered in the image. For example, the silhouette may be cropped by computing a bounding rectangle around the silhouette 274. The silhouette 274 may then be resized according to s, which as expressed above with respect to equation (1), is a function of a known height h of the user represented in the existing 2D body image that is to be updated.

Each silhouette 274 representative of the face may then be processed to determine facial traits or features of the face of the human body. For example, different CNNs may be trained using silhouettes of faces, such as human faces, from different orientations with known features. In some implementations, different CNNs may be trained for different orientations. For example, a first CNN 276A-1 may be trained to determine front view features from front view silhouettes 274-1. A second CNN 276A-2 may be trained to determine right side features from right side silhouettes. A third CNN 276A-3 may be trained to determine left side features from left side silhouettes. Different CNNs 276A-1 through 276A-N may be trained for each of the different orientations of silhouettes 274-1 through 274-N. Alternatively, one CNN may be trained to determine features from any orientation silhouette.

In implementations that utilize multiple images of the face 273 to produce multiple sets of features, such as the example illustrated in FIG. 2C, those features may be concatenated 276B and the concatenated features processed together with a CNN to generate a set of face-based predicted body features 277. For example, a CNN may be trained to receive features generated from different silhouettes 274 to produce face-based predicted body features 277. The face-based predicted body features 277 may indicate any aspect or information related to the body 273 for which the features are being predicted. For example, the face-based predicted body features 277 may indicate body volume, shape of the body, etc. In some implementations, the CNN 276B may be trained to predict hundreds of face-based body features 277 corresponding to the body 273 based at least in part on the face images.

Utilizing the face-based predicted body features 277 and the body features previously generated for the body 209, the body features are updated to produce a body model update 278 of the body. For example, the body features 209 previously generated for the body may be updated with face-based predicted body features to produce a body model update 278. In some implementations, the face-based predicted body features may be less than all of the previously determined body features. In such an implementation, the face-based predicted body features may be combined or used to update all of the body features, for example based on a change between the corresponding face-based predicted body features and the previously determined body features. For example, if the face-based predicted body features include a body volume feature but not a leg shape parameter, in some implementations, a difference or ratio between the body volume features of the face-based body features and the body volume of the body features may be determined. That difference or ratio may then be used to update the leg shape feature and/or other features for the body model. In other examples, the face-based predicted body features may correspond to all of the predicted body features such that all of the predicted body features for the body may be updated based on the face-based predicted body features.

In some implementations, the body model update may be augmented with one or more textures, texture augmentation 282, determined from one or more of the 2D face images 272-1 through 272-N and/or previously determined from one or more 2D body images. For example, the updated body model may be augmented to have a same or similar color to a skin color determined from the 2D face images 272 and clothing or clothing colors may be added as determined from the prior 2D body images.

The result of the processing illustrated in the transition 270 is a dimensionally accurate body model 284 or avatar representative of the body of the user, that has been generated from 2D body images of the body of the user and subsequently updated based on 2D face images of the face of the user.

As discussed above, features or objects expressed in imaging data, such as human bodies, colors, textures or outlines of the features or objects, may be extracted from the data in any number of ways. For example, colors of pixels, or of groups of pixels, in a digital image may be determined and quantified according to one or more standards, e.g., the RGB (“red-green-blue”) color model, in which the portions of red, green or blue in a pixel are expressed in three corresponding numbers ranging from 0 to 255 in value, or a hexadecimal model, in which a color of a pixel is expressed in a six-character code, wherein each of the characters may have a range of sixteen. Moreover, textures or features of objects expressed in a digital image may be identified using one or more computer-based methods, such as by identifying changes in intensities within regions or sectors of the image, or by defining areas of an image corresponding to specific surfaces.

Furthermore, edges, contours, outlines, colors, textures, segmented silhouettes, shapes or other characteristics of objects, or portions of objects, expressed in images may be identified using one or more algorithms or machine-learning tools. The objects or portions of objects may be identified at single, finite periods of time, or over one or more periods or durations. Such algorithms or tools may be directed to recognizing and marking transitions (e.g., the edges, contours, outlines, colors, textures, segmented silhouettes, shapes or other characteristics of objects or portions thereof) within the digital images as closely as possible, and in a manner that minimizes noise and disruptions, and does not create false transitions. Some detection algorithms or techniques that may be utilized in order to recognize characteristics of objects or portions thereof in digital images in accordance with the present disclosure include, but are not limited to, Canny edge detectors or algorithms; Sobel operators, algorithms or filters; Kayyali operators; Roberts edge detection algorithms; Prewitt operators; Frei-Chen methods; semantic segmentation algorithms; background subtraction; or any other algorithms or techniques that may be known to those of ordinary skill in the pertinent arts.

Image processing algorithms, other machine learning algorithms or CNNs may be operated on computer devices of various sizes or types, including but not limited to smartphones or other cell phones, tablets, video cameras or other computer-based machines. Such mobile devices may have limited available computer resources, e.g., network bandwidth, storage capacity or processing power, as compared to larger or more complex computer devices. Therefore, executing computer vision algorithms, other machine learning algorithms, or CNNs on such devices may occupy all or much of the available resources, without any guarantee, or even a reasonable assurance, that the execution of such algorithms will be successful. For example, processing digital 2D body images captured by a user of a portable device (e.g., smartphone, tablet, laptop, webcam) according to one or more algorithms in order to produce a body model from the digital images may be an ineffective use of the limited resources that are available on the smartphone or tablet. Accordingly, in some implementations, as discussed herein, some or all of the processing may be performed by one or more computing resources that are remote from the portable device. In some implementations, initial processing of the images to generate binary segmented silhouettes may be performed on the device. Subsequent processing to generate and refine the body model may be performed on one or more remote computing resources. For example, the segmented silhouettes may be sent from the portable device to the remote computing resources for further processing. Still further, in some implementations, texture augmentation of the body model of the body may be performed on the portable device or remotely.

In some implementations, to increase privacy of the user, only the binary segmented silhouette may be sent from the device for processing on the remote computing resources and the original 2D images that include the representation of the user may be maintained locally on the portable device. In such an example, the rendered body model may be sent back to the device and the device may perform texture augmentation of the received body model based on those images. Utilizing such a distributed computing arrangement retains user identifiable information on the portable device of the user while at the same time leveraging the increased computing capacity available at remote computing resources.

In still other examples, processing of the face images may be performed on the device and only face-based body features provided to remote systems. Alternatively, in other examples, processing of the face images to produce face-based body features as well as updating the body features based on the face-based body features may be performed on the device.

Machine learning tools, such as artificial neural networks, have been utilized to identify relations between respective elements of apparently unrelated sets of data. An artificial neural network, such as CNN, is a parallel distributed computing processor comprised of individual units that may collectively learn and store experimental knowledge, and make such knowledge available for use in one or more applications. Such a network may simulate the non-linear mental performance of the many neurons of the human brain in multiple layers by acquiring knowledge from an environment through one or more flexible learning processes, determining the strengths of the respective connections between such neurons, and utilizing such strengths when storing acquired knowledge. Like the human brain, an artificial neural network may use any number of neurons in any number of layers, including an input layer, an output layer, and one or more intervening hidden layers. In view of their versatility, and their inherent mimicking of the human brain, machine learning tools including not only artificial neural networks but also nearest neighbor methods or analyses, factorization methods or techniques, K-means clustering analyses or techniques, similarity measures such as log likelihood similarities or cosine similarities, latent Dirichlet allocations or other topic models, or latent semantic analyses have been utilized in image processing applications.

Artificial neural networks may be trained to map inputted data to desired outputs by adjusting the strengths of the connections between one or more neurons, which are sometimes called synaptic weights. An artificial neural network may have any number of layers, including an input layer, an output layer, and any number of intervening hidden layers. Each of the neurons in a layer within a neural network may receive one or more inputs and generate one or more outputs in accordance with an activation or energy function, with features corresponding to the various strengths or synaptic weights. Likewise, each of the neurons within a network may be understood to have different activation or energy functions; in this regard, such a network may be dubbed a heterogeneous neural network. In some neural networks, at least one of the activation or energy functions may take the form of a sigmoid function, wherein an output thereof may have a range of zero to one or 0 to 1. In other neural networks, at least one of the activation or energy functions may take the form of a hyperbolic tangent function, wherein an output thereof may have a range of negative one to positive one, or −1 to +1. Thus, the training of a neural network according to an identity function results in the redefinition or adjustment of the strengths or weights of such connections between neurons in the various layers of the neural network, in order to provide an output that most closely approximates or associates with the input to the maximum practicable extent.

Artificial neural networks may typically be characterized as either feedforward neural networks or recurrent neural networks, and may be fully or partially connected. In a feedforward neural network, e.g., a convolutional neural network, information specifically flows in one direction from an input layer to an output layer, while in a recurrent neural network, at least one feedback loop returns information regarding the difference between the actual output and the targeted output for training purposes. Additionally, in a fully connected neural network architecture, each of the neurons in one of the layers is connected to all of the neurons in a subsequent layer. By contrast, in a sparsely connected neural network architecture, the number of activations of each of the neurons is limited, such as by a sparsity parameter.

Moreover, the training of a neural network is typically characterized as supervised or unsupervised. In supervised learning, a training set comprises at least one input and at least one target output for the input. Thus, the neural network is trained to identify the target output, to within an acceptable level of error. In unsupervised learning of an identity function, such as that which is typically performed by a sparse autoencoder, target output of the training set is the input, and the neural network is trained to recognize the input as such. Sparse autoencoders employ backpropagation in order to train the autoencoders to recognize an approximation of an identity function for an input, or to otherwise approximate the input. Such backpropagation algorithms may operate according to methods of steepest descent, conjugate gradient methods, or other like methods or techniques, in accordance with the systems and methods of the present disclosure. Those of ordinary skill in the pertinent art would recognize that any algorithm or method may be used to train one or more layers of a neural network. Likewise, any algorithm or method may be used to determine and minimize the error in an output of such a network. Additionally, those of ordinary skill in the pertinent art would further recognize that the various layers of a neural network may be trained collectively, such as in a sparse autoencoder, or individually, such that each output from one hidden layer of the neural network acts as an input to a subsequent hidden layer.

Once a neural network has been trained to recognize dominant characteristics of an input of a training set, e.g., to associate an image with a label, a category, a cluster or a pseudo label thereof, to within an acceptable tolerance, an input and/or multiple inputs, in the form of an image, segmented silhouette, features, known traits corresponding to the image, etc., may be provided to the trained network, and an output generated therefrom. For example, the CNN discussed above may receive as inputs a generated segmented silhouette and one or more body attributes (e.g., height, weight, gender) corresponding to the body represented by the segmented silhouette. The trained CNN may then produce as outputs the predicted features corresponding to those inputs.

Referring to FIG. 3 , a block diagram of components of one image processing system 300 in accordance with implementations of the present disclosure is shown.

The system 300 of FIG. 3 includes a body composition system 310, an imaging element 320 that is part of a portable device 330 of a user, such as a tablet, a laptop, a cellular phone, a webcam, etc., and an external media storage facility 370 connected to one another across a network 380, such as the Internet.

The body composition system 310 of FIG. 3 includes M physical computer servers 312-1, 312-2 . . . 312-M having one or more databases (or data stores) 314 associated therewith, as well as N computer processors 316-1, 316-2 . . . 316-N provided for any specific or general purpose. For example, the body composition system 310 of FIG. 3 may be independently provided for the exclusive purpose of generating body models from 2D body images captured by imaging elements, such as imaging element 320, or segmented silhouettes produced therefrom, or, alternatively, provided in connection with one or more physical or virtual services configured to manage or monitor such information, as well as one or more other functions. The servers 312-1, 312-2 . . . 312-M may be connected to or otherwise communicate with the databases 314 and the processors 316-1, 316-2 . . . 316-N. The databases 314 may store any type of information or data, including simulated segmented silhouettes, body features, simulated body models, simulated partial segmented silhouettes, etc. The servers 312-1, 312-2 . . . 312-M and/or the computer processors 316-1, 316-2 . . . 316-N may also connect to or otherwise communicate with the network 380, as indicated by line 318, through the sending and receiving of digital data.

The imaging element 320 may comprise any form of optical recording sensor or device that may be used to photograph or otherwise record information or data regarding a body of the user, or for any other purpose. As is shown in FIG. 3 , the portable device 330 that includes the imaging element 320 is connected to the network 380 and includes one or more sensors 322, one or more memory or storage components 324 (e.g., a database or another data store), one or more processors 326, and any other components that may be required in order to capture, analyze and/or store imaging data, such as the 2D body images discussed herein. For example, the imaging element 320 may capture one or more still or moving images and may also connect to or otherwise communicate with the network 380, as indicated by the line 328, through the sending and receiving of digital data. Although the system 300 shown in FIG. 3 includes just one imaging element 320 therein, any number or type of imaging elements, portable devices, or sensors may be provided within any number of environments in accordance with the present disclosure.

The portable device 330 may be used in any location and any environment to generate 2D body images that represent a body of the user. In some implementations, the portable device may be positioned such that it is stationary and approximately vertical (within approximately ten-degrees of vertical) and the user may position their body within a field of view of the imaging element 320 of the portable device at different orientations so that the imaging element 320 of the portable device may generate 2D body images that include a representation of the body of the user from different orientations.

The portable device 330 may also include one or more applications 323 stored in memory that may be executed by the processor 326 of the portable device to cause the processor of the portable device to perform various functions or actions. For example, when executed, the application 323 may provide instructions to a user regarding placement of the portable device, positioning of the body of the user within the field of view of the imaging element 320 of the portable device, orientation of the body of the user, etc. Likewise, in some implementations, the application may present a body model, generated from the 2D body images in accordance with the described implementations, to the user and allow the user to interact with the body model. For example, a user may rotate the body model to view different angles of the body model, obtain approximately accurate measurements of the body of the user from the dimensions of the body model, view body fat, body mass, volume, etc. Likewise, in some implementations, the body model may be modified by request of the user to simulate what the body of the user may look like under certain conditions, such as loss of weight, gain of muscle, etc.

The external media storage facility 370 may be any facility, station or location having the ability or capacity to receive and store information or data, such as segmented silhouettes, simulated or rendered body models of bodies, textures, body dimensions, etc., received from the body composition system 310, and/or from the portable device 330. As is shown in FIG. 3 , the external media storage facility 370 includes J physical computer servers 372-1, 372-2 . . . 372-J having one or more databases 374 associated therewith, as well as K computer processors 376-1, 376-2 . . . 376-K. The servers 372-1, 372-2 . . . 372-J may be connected to or otherwise communicate with the databases 374 and the processors 376-1, 376-2 . . . 376-K. The databases 374 may store any type of information or data, including digital images, segmented silhouettes, body models, etc. The servers 372-1, 372-2 . . . 372-J and/or the computer processors 376-1, 376-2 . . . 376-K may also connect to or otherwise communicate with the network 380, as indicated by line 378, through the sending and receiving of digital data.

The network 380 may be any wired network, wireless network, or combination thereof, and may comprise the Internet in whole or in part. In addition, the network 380 may be a personal area network, local area network, wide area network, cable network, satellite network, cellular telephone network, or combination thereof. The network 380 may also be a publicly accessible network of linked networks, possibly operated by various distinct parties, such as the Internet. In some implementations, the network 380 may be a private or semi-private network, such as a corporate or university intranet. The network 380 may include one or more wireless networks, such as a Global System for Mobile Communications (GSM) network, a Code Division Multiple Access (CDMA) network, a Long Term Evolution (LTE) network, or some other type of wireless network. Protocols and components for communicating via the Internet or any of the other aforementioned types of communication networks are well known to those skilled in the art of computer communications and, thus, need not be described in more detail herein.

The computers, servers, devices and the like described herein have the necessary electronics, software, memory, storage, databases, firmware, logic/state machines, microprocessors, communication links, displays or other visual or audio user interfaces, printing devices, and any other input/output interfaces to provide any of the functions or services described herein and/or achieve the results described herein. Also, those of ordinary skill in the pertinent art will recognize that users of such computers, servers, devices and the like may operate a keyboard, keypad, mouse, stylus, touch screen, or other device (not shown) or method to interact with the computers, servers, devices and the like, or to “select” an item, link, node, hub or any other aspect of the present disclosure.

The body composition system 310, the portable device 330 or the external media storage facility 370 may use any web-enabled or Internet applications or features, or any other client-server applications or features including E-mail or other messaging techniques, to connect to the network 380, or to communicate with one another, such as through short or multimedia messaging service (SMS or MMS) text messages. For example, the servers 312-1, 312-2 . . . 312-M may be adapted to transmit information or data in the form of synchronous or asynchronous messages from the body composition system 310 to the processor 326 or other components of the portable device 330, or any other computer device in real time or in near-real time, or in one or more offline processes, via the network 380. Those of ordinary skill in the pertinent art would recognize that the body composition system 310, the portable device 330 or the external media storage facility 370 may operate any of a number of computing devices that are capable of communicating over the network, including but not limited to set-top boxes, personal digital assistants, digital media players, web pads, laptop computers, desktop computers, electronic book readers, cellular phones, and the like. The protocols and components for providing communication between such devices are well known to those skilled in the art of computer communications and need not be described in more detail herein.

The data and/or computer executable instructions, programs, firmware, software and the like (also referred to herein as “computer executable” components) described herein may be stored on a computer-readable medium that is within or accessible by computers or computer components such as the servers 312-1, 312-2 . . . 312-M, the processor 326, the servers 372-1, 372-2 . . . 372-J, or any other computers or control systems utilized by the body composition system 310, the portable device 330, applications 323, or the external media storage facility 370, and having sequences of instructions which, when executed by a processor (e.g., a central processing unit, or “CPU”), cause the processor to perform all or a portion of the functions, services and/or methods described herein. Such computer executable instructions, programs, software and the like may be loaded into the memory of one or more computers using a drive mechanism associated with the computer readable medium, such as a floppy drive, CD-ROM drive, DVD-ROM drive, network interface, or the like, or via external connections.

Some implementations of the systems and methods of the present disclosure may also be provided as a computer-executable program product including a non-transitory machine-readable storage medium having stored thereon instructions (in compressed or uncompressed form) that may be used to program a computer (or other electronic device) to perform processes or methods described herein. The machine-readable storage media of the present disclosure may include, but is not limited to, hard drives, floppy diskettes, optical disks, CD-ROMs, DVDs, ROMs, RAMs, erasable programmable ROMs (“EPROM”), electrically erasable programmable ROMs (“EEPROM”), flash memory, magnetic or optical cards, solid-state memory devices, or other types of media/machine-readable medium that may be suitable for storing electronic instructions. Further, implementations may also be provided as a computer executable program product that includes a transitory machine-readable signal (in compressed or uncompressed form). Examples of machine-readable signals, whether modulated using a carrier or not, may include, but are not limited to, signals that a computer system or machine hosting or running a computer program can be configured to access, or including signals that may be downloaded through the Internet or other networks.

FIG. 4 is a block diagram of a trained body composition model 400 that determines predicted body features 407 of a body represented in two-dimensional images and/or generated face-based predicted body features for a body, in accordance with implementations of the present disclosure. As discussed above, the model 400 may be a neural network, such as a CNN that is trained to receive one or more inputs that are processed to generate one or more outputs, such as the predicted body features 407, which may be body features predicted from a 2D body image of a body and/or face-based predicted body features predicted from a 2D face image corresponding to the body. In the illustrated example, the trained body composition model 406 may include several component CNNs that receive different inputs and provide different outputs. Likewise, outputs from one of the component CNNs may be provided as an input to one or more other component CNNs of the trained body composition model. For example, the trained body composition model may include four parts of component CNNs. In one implementation, a first component part may include one or more feature determination CNNs 406A, a second component part may include a visibility determination CNN 406B, and a third component part may include a concatenation CNN 406C, and a fourth component part may include a face-based feature determination CNN 406D. In the illustrated example, there may be different feature determination CNNs 406A for each of the different body orientations (e.g., front view, right side view, back view, left side view, three-quarter view), different segmented silhouettes 404 corresponding to those different body orientations, and/or different 2D body images corresponding to those different body orientations, each CNN trained for inputs having the particular orientation. Likewise, in some implementations, the feature determination CNNs 406A may receive multiple different types of inputs. For example, in addition to receiving a segmented silhouette 404 and/or 2D body image, each feature determination CNN 406A may receive one or more body attributes 405 corresponding to the body represented by the segmented silhouettes 404 and/or 2D body images. The body attributes 405 may include, but are not limited to, height, weight, gender, etc. As discussed, the trained feature determination CNNs 406A process the inputs and generate features representative of the bodies represented in the 2D body images that were used to produce the segmented silhouettes 404. For example, if there are four segmented silhouettes, one for a front view, one for a right side view, one for a back view, and one for a left side view, the four feature determination CNNs 406A trained for those views each produce a set of features representative of the body represented in the 2D body image used to generate the segmented silhouette.

Utilizing segmented silhouettes 404 of bodies improves the accuracy of the feature determination CNN 406A as it can focus purely on size, shape, dimensions, etc., of the body, devoid of any other aspects (e.g., color, clothing, hair, etc.). In other implementations, the use of the 2D body images in conjunction with or independent of the segmented silhouettes provides additional data, such as shadows, skin tone, etc., that the feature determination CNN 406A may utilize in determining and producing a set of features representative of the body represented in the 2D body image.

Likewise, there may be different visibility determination CNNs 406B for each of the different body orientations (e.g., front view, right side view, back view, left side view, three-quarter view), different segmented silhouettes 404 corresponding to those different body orientations, and/or different 2D body images corresponding to those different body orientations, each CNN trained for inputs having the particular orientation. Likewise, in some implementations, the visibility determination CNNs 406B may receive multiple different types of inputs. For example, in addition to receiving a segmented silhouette 404 and/or 2D body image, each visibility determination CNN 406B may receive from each of the feature determination CNNs 406A body 2D landmarks and determine whether those body 2D landmarks are visible in the 2D body image. For each body 2D landmark, the visibility determination CNN 406B determines a visibility indicator indicative of whether the 2D landmark is visible in the corresponding 2D image.

The features output from the feature determination CNNs 406A and the visibility indicators output from the visibility determination CNNs 406B, in the disclosed implementation, are received as inputs to the concatenation CNN 406C. Likewise, in some implementations, the concatenation CNN 406C may be trained to receive other inputs, such as body attributes 405.

As discussed, the concatenation CNN 406C may be trained to receive the inputs of features, visibility indicators, and optionally other inputs, produce concatenated features, and produce as outputs a set of predicted body features 407 corresponding to the body represented in the 2D body images. In some implementations, the predicted body features may include hundreds of features, including, but not limited to, shape, pose, volume, 2D landmark, visibility indicators for each 2D landmark, etc., of the represented body.

The face-based feature determination CNNs 406D may receive as inputs the body features output by the concatenation CNNs 406C as well as 2D face images. In the illustrated example, there may be different face-based feature determination CNNs 406D for each of the different face orientations (e.g., front view, right side view, left side view, three-quarter view), different segmented silhouettes corresponding to those different face orientations, and/or different 2D face images corresponding to those different orientations, each CNN trained for inputs having the particular orientation. Likewise, in some implementations, the face-based feature determination CNNs 406D may receive multiple different types of inputs. For example, in addition to receiving a segmented silhouette 404 and/or 2D face image, each face-based feature determination CNN 406D may receive one or more body attributes 405 corresponding to the body for which updated body features are to be determined from a face image and/or existing body features. As discussed, the trained face-based feature determination CNNs 406D process the inputs and generate, based on a face image(s), features representative of the bodies corresponding to those face images and that were used to create the body attributes. For example, if there are three segmented silhouettes generated from the face image, one for a front view, one for a right side view, and one for a left side view, the three feature determination CNNs 406D trained for those views each produce a set of features representative of the body corresponding to the face image used to generate the segmented silhouette.

FIG. 5 is an example flow diagram of a three-dimensional body model generation process 500, in accordance with implementations of the present disclosure.

The example process 500 begins upon receipt of one or more 2D body images of a body, as in 502. As noted above, the disclosed implementations are operable with any number of 2D body images for use in generating a body model of that body. For example, in some implementations, a single 2D body image may be used. In other implementations, two, three, four, or more 2D body images may be used.

As discussed above, the 2D body images may be generated using any 2D imaging element, such as a camera on a portable device, a webcam, etc. The received 2D body images are then segmented to produce a segmented silhouette of the body represented in the one or more 2D body images, as in 504. As discussed above, the 2D body images may be processed by a CNN that is trained to identify body segments (e.g., hair, head, neck, upper arm, etc.) and generate a vector for each pixel of the 2D body image, the vector including prediction scores for each potential body segment (label) indicating a likelihood that the pixel corresponds to the body segment.

In addition, in some implementations, the segmented silhouettes may be normalized in height and centered in the image before further processing, as in 506. For example, the segmented silhouettes may be normalized to a standard height based on a function of a known or provided height of the body of the user represented in the image and an average height (e.g., average height of female body, average height of male body). In some implementations, the average height may be more specific than just gender. For example, the average height may be the average height of a gender and a race corresponding to the body, or a gender and a location (e.g., United States) of the user, etc.

The normalized and centered segmented silhouette may then be processed by one or more neural networks, such as one or more CNNs as discussed above, to generate predicted body features representative of the body represented in the 2D body images, as in 508. As discussed above, there may be multiple steps involved in body feature prediction. For example, each segmented silhouette may be processed using CNNs trained for the respective orientation of the segmented silhouette to generate sets of features of the body as determined from the segmented silhouette. The sets of features generated from the different segmented silhouettes may then be processed using a neural network, such as a CNN, to concatenate the features and generate the predicted body features representative of the body represented in the 2D body images.

The predicted body features may then be provided to one or more body models, such as an SMPL body model or a SCAPE body model and the body model may generate a body model for the body represented in the 2D body images, as in 510. In addition, in some implementations, the body model may be revised, if necessary, to more closely correspond to the actual image of the body of the user, as in 512. Body model refinement is discussed above, and discussed further below with respect to FIGS. 6A and 6B.

As discussed below, the body model adjustment process 600 (FIG. 6A) returns an adjusted segmented silhouette, as in 514. Upon receipt of the adjusted segmented silhouette, the example process 500 again generates predicted body features, as in 508, and continues. This may be done until no further refinements are to be made to the segmented silhouette. In comparison, the body model refinement process 650 (FIG. 6B) generates and returns an adjusted body model and the example process 500 continues at block 516.

After adjustment of the segmented silhouette and generation of a body model from adjusted body features, or after receipt of the adjusted body model from FIG. 6B, one or more textures (e.g., skin tone, hair, clothing, etc.) from the 2D body images may be applied to the body model, as in 516. Applying texture to the body model is discussed further below with respect to FIG. 7 . Finally, the body model may be provided to the user as representative of the body of the user and/or other body model information (e.g., body mass, 2D landmarks, arm length, body fat percentage, etc.) may be determined from the model, as in 518.

FIG. 6A is an example flow diagram of a body model adjustment process 600, in accordance with implementations of the present disclosure. The example process 600 begins by determining a pose of a body represented in one of the 2D body images, as in 602. A variety of techniques may be used to determine the approximate pose of the body represented in a 2D body image. For example, camera features (e.g., camera type, focal length, shutter speed, aperture, etc.) included in the metadata of the 2D body image may be obtained and/or additional camera features may be determined and used to estimate the approximate pose of the body represented in the 2D body image. For example, a body model may be used to approximate the pose of the body in the 2D body image and then a position of a virtual camera with respect to that model that would produce the 2D body image of the body may be determined. Based on the determined position of the virtual camera, the height and angle of the camera used to generate the 2D body image may be inferred. In some implementations, the camera tilt may be included in the metadata and/or provided by a portable device that includes the camera. For example, many portable devices include an accelerometer and information from the accelerometer at the time the 2D body image was generated may be provided as the tilt of the camera. Based on the received and/or determined camera features, the pose of the body represented in the 2D body image with respect to the camera may be determined, as in 602.

The body model of the body of the user may then be adjusted to correspond to the determined pose of the body in the 2D body image, as in 604. A determination is then made as to which 2D landmarks of the body are visible in the 2D body image, as in 606. For example, a defined set of 2D landmarks (e.g., left shoulder, right shoulder, left elbow, right elbow, right hip, left hip, etc.) may be defined and the 2D body image, segmented silhouette, and/or body model of the body may be processed to determine which of the set of 2D landmarks are visible in the 2D image.

For each 2D landmark that is determined to be visible in the 2D body image, the corresponding landmark in the body model is adjusted to correspond to the 2D landmark in the 2D body image, as in 608. For example, the coordinates of the body model may be overlaid with the 2D body image and the landmarks of the body model updated to correspond to the respective 2D landmarks as represented in the 2D body image. In some implementations, the location and/or shape of the body segments of the body model between landmarks may also be updated to correspond or align with the updated landmarks of the body model. For 2D landmarks that are determined to be invisible, for example the 2D landmark may be beyond the field of view represented in the image or occluded by another object represented in the image, the position data for that 2D landmark may not be considered and the landmark in the body model not adjusted based on the 2D landmark determined from the 2D body image. However, in some implementations, the landmark of the body model that corresponds to a 2D landmark that is determined to not be visible in the 2D body image may be adjusted based on the repositioning of other 2D landmarks that are visible in the 2D body image.

With the body model adjusted to approximately the same pose as the user represented in the 2D body image and the landmarks of the body model aligned with the visible 2D landmarks of the 2D body image, the shape and position of each body segment of the body model may be compared to the shape of the corresponding visible body segments in the 2D body image and/or the body segments in the segmented silhouette to determine any differences between the body segments of the body model and the representation of the visible body segments in the 2D body image and/or segmented silhouette, as in 610. In the disclosed implementations, the visibility indicator determined for each body segment may be utilized to determine whether to compare the body model segment with the body segment of the 2D body image and/or the segmented silhouette. For example, if the visibility indicator indicates that the body segment, or a portion thereof, is not visible in the 2D body image, the data represented in the segmented silhouette may be unreliable and therefore not utilized in determining the body model.

Additionally, in some implementations, for visible body segments represented in the 2D body image, it may be determined whether any determined difference is above a minimum threshold (e.g., 2%). If it is determined that there is a difference between a body segment of the body model and the body segment represented in one or more of the 2D body images, the segmented silhouette may be adjusted, as in 612. The adjustment of body segments of the segmented silhouette may be performed in an iterative fashion taking into consideration the difference determined for each body segment and adjusting the visible body segments. The revised segmented silhouette may then be used to generate revised body features for the body represented in the 2D body images, as discussed above with respect to FIG. 5 . If the segmented silhouette is revised, the revised segmented silhouette is returned to the example process 500, as discussed above and as illustrated in block 514 (FIG. 5 ). If no difference is determined or if it is determined that the difference does not exceed a minimum threshold, an indication may be returned to the example process 500 that there are no differences between the body model and the 2D body image/segmented silhouette.

FIG. 6B is an example flow diagram of another body model adjustment process 650, in accordance with implementations of the present disclosure.

The example process 650 begins by determining a pose of a body represented in one of the 2D body images, as in 652. A variety of techniques may be used to determine the approximate pose of the body represented in a 2D body image. For example, camera features (e.g., camera type, focal length, shutter speed, aperture, etc.) included in the metadata of the 2D body image may be obtained and/or additional camera features may be determined and used to estimate the approximate pose of the body represented in the 2D body image. For example, a body model may be used to approximate the pose of the body in the 2D body image and then a position of a virtual camera with respect to that model that would produce the 2D body image of the body may be determined. Based on the determined position of the virtual camera, the height and angle of the camera used to generate the 2D body image may be inferred. In some implementations, the camera tilt may be included in the metadata and/or provided by a portable device that includes the camera. For example, many portable devices include an accelerometer and information from the accelerometer at the time the 2D body image was generated may be provided as the tilt of the camera. Based on the received and/or determined camera features, the pose of the body represented in the 2D body image with respect to the camera may be determined, as in 652.

The body model of the body of the user may then be adjusted to correspond to the determined pose of the body in the 2D body image, as in 654. A determination is then made as to which 2D landmarks of the body are visible in the 2D body image, as in 656. For example, a defined set of 2D landmarks (e.g., left shoulder, right shoulder, left elbow, right elbow, right hip, left hip, etc.) may be defined and the 2D body image, segmented silhouette, and/or body model of the body may be processed to determine which of the set of 2D landmarks are visible in the 2D image.

For each 2D landmark that is determined to be visible in the 2D body image, the corresponding landmark in the body model is adjusted to correspond to the 2D landmark in the 2D body image, as in 658. For example, the coordinates of the body model may be overlaid with the 2D body image and the body landmarks of the body model updated to correspond to the 2D landmarks as represented in the 2D body image. In some implementations, the location and/or shape of the body segments of the body model between landmarks may also be updated to correspond or align with the updated landmarks of the body model. For 2D landmarks that are determined to be invisible, for example the 2D landmark may be beyond the field of view represented in the image or occluded by another object represented in the image, the position data for that 2D landmark may not be considered and the landmark in the body model not adjusted based on the 2D landmark determined from the 2D body image. However, in some implementations, the landmark of the body model that corresponds to a 2D landmark that is determined to not be visible in the 2D body image may be adjusted based on the repositioning of other 2D landmarks that are visible in the 2D body image.

With the body model adjusted to approximately the same pose as the user represented in the image and the landmarks of the body model aligned with the visible 2D landmarks of the 2D body image, a 2D model image from the body model is generated, as in 660. The 2D model image may be generated, for example, by converting or imaging the body model into a 2D model image with the determined pose, as if a digital 2D model image of the body model had been generated. Likewise, the 2D model image may be segmented to include body segments corresponding to body segments determined for the body model.

The body segments of the 2D model image are then compared with the visible body segments of the 2D body image and/or the segmented silhouette to determine any differences between the 2D model image and the representation of visible body segments of the body in the 2D body image and/or segmented silhouette, as in 662. For example, the 2D model image may be aligned with the 2D body image and/or the segmented silhouette and pixels of each corresponding body segment that is visible in the 2D body image compared to determine differences between the pixel values. In implementations in which the pixels of body segments are assigned different color values, an error (e.g., % difference) may be determined as a difference in pixel values between the 2D model image and the 2D body image for each segment. For body segments that are determined to be not visible in the 2D body image, the pixel values may not be compared. The error determined for visible body segments is differentiable and may be utilized to adjust the size, shape, and/or position of each body segment and the resulting predicted body features, thereby updating the shape of the body model.

In some implementations, for visible body segments, it may be determined whether any determined difference is above a minimum threshold (e.g., 2%). If it is determined that there is a difference between a body segment of the 2D model image and the body segment represented in one or more of the 2D body images/segmented silhouette, the segment in the body model and/or the predicted body features may be adjusted to correspond to the shape and/or size of the body segment represented in the 2D body image and/or the segmented silhouette, as in 664. This example process 650 may continue until there is no difference between the segments of the 2D model image and the visible body segments represented in the 2D body image/segmented silhouette, or the difference is below a minimum threshold. As discussed above, the revised body model produced from the example process 650, or if no adjustments are necessary, the body model is returned to example process 500 at block 512 and the process 500 continues.

FIG. 7 is an example texturing process 700, in accordance with disclosed implementations. The example process may be performed to apply texturing, such as skin color, hair, clothing, etc., to a body model of a body.

The example process 700 begins by selecting a segment of a body model to be textured, as in 702. In some implementations, the segment may be randomly selected. In other implementations, the example process 700 may first process all body segments that are determined to be visible in the corresponding 2D body image before processing body segments that are determined to be not visible in the corresponding 2D body image.

For the selected body segment, a determination is made as to whether the corresponding segment in the 2D body image is visible, as in 704. If it is determined that the corresponding segment is visible in the 2D body image, the texture of the segment, as represented in the 2D body image, is applied to the body model, as in 706. Applying texture to a body model is known in the art and need not be discussed herein in detail.

If it is determined that the selected body segment is determined to not be visible in the corresponding 2D body image, the texture from adjacent body segments are determined and used to predict a texture for the selected body segment, as in 708. In some implementations, the prediction may be performed only based on adjacent segments that have been determined to be visible in the 2D body image. In other implementations, the example process 700 may consider other factors such as the body segment to be predicted, the user, textures typically used for the body segment, etc., in determining a predicted texture of the body segment. For example, if the body segment is a waist of a user, the example process may determine that the segment will likely include lower clothing and may not utilize a predicted texture from an adjacent upper leg segment. As another example, the disclosed implementations may refer to a prior body model generated for the user and/or other users or groups of users to determine a texture for one or more body segments that are not visible in the 2D body image. The predicted texture, however determined, is then applied to the selected body segment, as in 710.

After applying the texture of a visible body segment as determined from the 2D body image or applying a predicted texture to the selected segment, a determination is made as to whether additional segments of the body are to be textured, as in 712. If it is determined that additional segments are to be textured, the example process 700 returns to block 702 and continues. If it is determined that no additional segments are to be textured, the example process 700 completes, as in 714. Upon completion of the example process 700, the textured body model may be returned to the example process 500 (FIG. 5 ) as discussed above.

FIG. 8 is an example flow diagram of a body model update process 800, in accordance with implementations of the present disclosure.

The example process 800 begins by determining if a time since a last body model generation for the body exceeds a threshold, as in 802. The threshold may be any number, value, or other indicator and may be different for different users, different body types, different times of the year, etc.

If it is determined that the time since body model generation exceeds the threshold, the body model generation process 500 (FIG. 5 ) is performed, as in 804, and a user may be requested to provide a body image for body model generation, rather than generating face-based predicted body features from a face image of the user.

If it is determined that the time since body model generation does not exceed the threshold, one or more 2D face images are obtained or otherwise received, as in 806. 2D face images may be obtained from any source approved by the user, such as a cell phone camera, laptop camera (e.g., during video calls), etc. Because of the simplicity of obtaining 2D face images of a user, the disclosed implementations may be performed frequently (e.g., daily) to monitor a health or progress of a user (e.g., progress on a weight loss journey), and/or to monitor other information about the user, as requested by the user.

As discussed above, the one or more 2D face images may be processed to generate a silhouette of the face represented in the face image, as in 808. The 2D face images may be processed by a CNN that is trained to identify facial segments (e.g., hair, head, neck, eyes, ears, mouth, nose, etc.) and from those facial features determine one or more body features for the body corresponding to the face.

In addition, in some implementations, the segmented silhouettes may be normalized in size and centered in the image before further processing, as in 810. For example, the face silhouettes may be normalized to a standard size based on a function of a known or provided ratio between the ears and eyes, eyes and mouth, etc. For example, the ratio between facial features of a user may be known by the disclosed implementations from prior body model generation of the body.

The normalized and centered silhouette of the face may then be processed by one or more neural networks, such as one or more CNNs as discussed above, to generate face-based predicted body features representative of the body corresponding to the face represented in the 2D face images, as in 812. As discussed above, there may be multiple steps involved in body feature prediction. For example, each face silhouette may be processed using CNNs trained for the respective orientation of the segmented silhouette to generate sets of features of the body as determined from the segmented silhouette and optionally based on features previously determined for the body, as discussed herein. The sets of features generated from the different face silhouettes may then be processed using a neural network, such as a CNN, to concatenate the features and generate the face-based predicted body features representative of the body corresponding to the face represented in the 2D face images.

In some implementations, a bias correction or adjustment may be made to account for bias introduced when generating face-based body features determined from face images, as in 814. For example, during training for the user, body features may be generated from a 2D body image, as discussed herein, and that same image(s) (other images taken concurrently therewith) may be cropped to only include the face. That face image may then be processed to determine face-based body features. A difference between the body features and the face-based body features may then be determined and utilized as a bias correction to adjust the face-based body features during operation.

A determination may then be made as to whether the bias adjusted face-based body features is within a threshold difference of the body features previously determined for the body, as in 816. The threshold may be any value or other indicator and may change based on a duration of time between the current face image processing and the prior body feature determination, may be different for different users, etc.

If it is determined that the face-based body features are within a difference threshold of the previously determined body features for the body, the body model and/or corresponding body features are updated based on the face-based body features determined from the face image, as in 820. In comparison, if it is determined that the face-based body features are not within the threshold difference of the previously computed body features, it may be requested that a new body model of the body of the user be generated based on a body image, as discussed herein, as in 818.

The updated predicted body features may then be provided to one or more body models, such as an SMPL body model or a SCAPE body model and the body model may be updated to generate an updated body model for the body corresponding to the face represented in the 2D face images, as in 822.

In addition, in some implementations, the texture of the updated body model may also be updated based on texture information determined from the 2D face images (e.g., skin tone, wrinkles, hair, piercings, etc.), as in 824.

Finally, the updated body model may be provided to the user as representative of the body of the user and/or other body model information (e.g., body mass, 2D landmarks, arm length, body fat percentage, etc.) may be determined from the model, as in 826.

While the above example discussed using face-based body features determined from a face of a body to update body features determined from a 2D body image of at least a portion of the body, in other examples, the disclosed implementations may utilize a 2D face image alone to determine one or more body features of a body and may provide those features without and/or independent of updating an existing body model. Still further, in some examples, the face-based body features determined from 2D face image may be used to generate a body model without use of a body model generated from a 2D body image.

FIG. 9 is an example flow diagram of a bias correction process 900, in accordance with implementations of the present disclosure.

The example process 900 begins by obtaining or determining body features from a 2D body image for a body, as in 902. As discussed above, body features for a body may be determined in accordance with the disclosed implementations from one or more full or partial body images of the body.

In addition to determining the body features from the body image, the body image, or another image of the body generated substantially concurrently with the 2D body image may be cropped to produce a face image that includes the face of the body but is significantly devoid of other portions of the body, as in 904. The face image may then be processed to determine face-based body features, as discussed herein, as in 906.

Finally, the bias correction may be defined as a difference, ratio, etc., between the determined body features and the determined face-based body features, as in 908. As discussed above, the bias correction may be applied during operation to face-based body features to adjust those features.

While the example process 900 discussed with respect to FIG. 9 describes generation of bias correction based on a single 2D body image and a single face image, it will be appreciated, that multiple body images and corresponding face images may be processed in accordance with the example process 900 and the results combined (e.g. averaged) to generate a bias correction.

Although the disclosure has been described herein using exemplary techniques, components, and/or processes for implementing the systems and methods of the present disclosure, it should be understood by those skilled in the art that other techniques, components, and/or processes or other combinations and sequences of the techniques, components, and/or processes described herein may be used or performed that achieve the same function(s) and/or result(s) described herein and which are included within the scope of the present disclosure.

Additionally, in accordance with the present disclosure, the training of machine learning tools (e.g., artificial neural networks or other classifiers) and the use of the trained machine learning tools to generate body models of a body based on one or more 2D images of that body or face of the body may occur on multiple, distributed computing devices, or on a single computing device.

Furthermore, although some implementations of the present disclosure reference the use of separate machine learning tools or separate CNNs for processing segmented silhouettes, for concatenating features determined from segmented silhouettes, for generating the body model of the body, and/or for updating a body model based on face images, the systems and methods of the present disclosure are not so limited. Features, predicted body features, and/or body models may be determined and generated using a single CNN, or with two or more CNNs, in accordance with the present disclosure.

Likewise, while the above discussions focus primarily on generating and updating a body model of a body using multiple 2D body images of the body, and/or face images corresponding to the body in some implementations, the body model may be generated based on a single 2D body image of the body and/or single face image corresponding to the body. In other implementations, two or more 2D body images of the body and/or two or more face images from different orientations may be used with the disclosed implementations. In general, the more 2D body images of the body from different orientations, and/or face images from different orientations, the more accurate the final representation and dimensions of the body model may be.

Still further, while the above implementations are described with respect to generating body models of human bodies represented in 2D body images, in other implementations, non-human bodies, such as dogs, cats, or other animals may be modeled in body based on 2D representations of those bodies. Accordingly, the use of a human body in the disclosed implementations should not be considered limiting.

It should be understood that, unless otherwise explicitly or implicitly indicated herein, any of the features, characteristics, alternatives or modifications described regarding a particular implementation herein may also be applied, used, or incorporated with any other implementation described herein, and that the drawings and detailed description of the present disclosure are intended to cover all modifications, equivalents and alternatives to the various implementations as defined by the appended claims. Moreover, with respect to the one or more methods or processes of the present disclosure described herein, including but not limited to the flow charts shown in FIGS. 5, 6A, 6B, 7, 8, and 9 or the transition diagrams shown in FIGS. 1A, 2A, and 2B, orders in which such methods or processes are presented are not intended to be construed as any limitation on the claimed inventions, and any number of the method or process steps or boxes described herein can be combined in any order and/or in parallel to implement the methods or processes described herein. Also, the drawings herein are not drawn to scale.

Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey in a permissive manner that certain implementations could include, or have the potential to include, but do not mandate or require, certain features, elements and/or steps. In a similar manner, terms such as “include,” “including” and “includes” are generally intended to mean “including, but not limited to.” Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular implementation.

The elements of a method, process, or algorithm described in connection with the implementations disclosed herein can be embodied directly in hardware, in a software module stored in one or more memory devices and executed by one or more processors, or in a combination of the two. A software module can reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, a hard disk, a removable disk, a CD-ROM, a DVD-ROM or any other form of non-transitory computer-readable storage medium, media, or physical computer storage known in the art. An example storage medium can be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The storage medium can be volatile or nonvolatile. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

Disjunctive language such as the phrase “at least one of X, Y, or Z,” or “at least one of X, Y and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain implementations require at least one of X, at least one of Y, or at least one of Z to each be present.

Unless otherwise explicitly stated, articles such as “a” or “an” should generally be interpreted to include one or more described items. Accordingly, phrases such as “a device configured to” are intended to include one or more recited devices. Such one or more recited devices can also be collectively configured to carry out the stated recitations. For example, “a processor configured to carry out recitations A, B and C” can include a first processor configured to carry out recitation A working in conjunction with a second processor configured to carry out recitations B and C.

Language of degree used herein, such as the terms “about,” “approximately,” “generally,” “nearly” or “substantially” as used herein, represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “about,” “approximately,” “generally,” “nearly” or “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.

Although the invention has been described and illustrated with respect to illustrative implementations thereof, the foregoing and various other additions and omissions may be made therein and thereto without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. A computer-implemented method, comprising: receiving a two-dimensional (“2D”) body image of a human body from a 2D camera; processing the 2D body image to determine a plurality of body features corresponding to the human body; generating, based at least in part on the 2D body image and the plurality of body features, a body model of the human body; subsequent to generating the body model, receiving a 2D face image of a face of the human body; processing the 2D face image to determine a plurality of face-based body features corresponding to a first sub-plurality of the plurality of body features of the human body; determining at least one of a difference or a ratio between the plurality of face-based body features and the corresponding first sub-plurality of body features; updating the first sub-plurality of body features based at least in part on the face-based body features to produce an updated first sub-plurality of body features corresponding to the human body; updating a second sub-plurality of the plurality of body features that are not included in the first sub-plurality of body features based at least in part on the difference or the ratio to produce an updated second sub-plurality of body features corresponding to the human body; generating, based at least in part on the updated first sub-plurality of body features and the updated second sub-plurality of body features, an updated body model of the human body; and presenting the updated body model of the human body.
 2. The computer-implemented method of claim 1, further comprising: determining that a difference between the plurality of face-based body features and the plurality of body features does not exceed a threshold; and wherein updating the first sub-plurality of body features and the second sub-plurality of body features is in response to determining that the difference does not exceed the threshold.
 3. The computer-implemented method of claim 1, further comprising: determining that a time duration has not been exceeded between generating the body model and receiving the 2D face image.
 4. The computer-implemented method of claim 1, further comprising: adjusting the face-based body features to account for a bias in processing the 2D face image.
 5. The computer-implemented method of claim 1, wherein: processing of the 2D face image is performed by a neural network trained to determine body features of a body based at least in part on the 2D face image.
 6. The computer-implemented method of claim 1, wherein the body model includes a three-dimensional rendering of the human body.
 7. A computing system, comprising: one or more processors; and a memory storing program instructions that when executed by the one or more processors cause the one or more processors to at least: receive a two-dimensional (“2D”) face image of a face of a body; process the 2D face image to determine a first face-based body feature corresponding to a first existing body feature stored for the body; determine at least one of a difference or a ratio between the first face-based body feature and the first existing body feature; generate, based at least in part on the first face-based body feature and the first existing body feature, an updated first body feature for the body; generate, based at least in part on one or more of the difference or the ratio and a second existing body feature stored for the body, an updated second body feature for the body; and provide at least the updated first body feature and the updated second body feature.
 8. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors further cause the one or more processors to at least: receive the 2D face image from a user device that generates the 2D face image during a user activity.
 9. The computing system of claim 8, wherein the user activity is at least one of, a self-photo of a user, an intentional face photo generated by the user, or a video meeting.
 10. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors further cause the one or more processors to at least: determine that a difference between the first face-based body feature and the first existing body feature does not exceed a threshold; and wherein generation of the updated first body feature and generation of the updated second body feature is in response to a determination that the difference does not exceed the threshold.
 11. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors further cause the one or more processors to at least: determine that a time duration has not been exceeded between generation of a body model of the body and receipt of the 2D face image.
 12. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors, further cause the one or more processors to at least: subsequent to generation of the updated first body feature, receive a second 2D face image; determine that a time duration between receipt of the second 2D face image and a generation of a body model of the body is exceeded; and in response to determination that the time duration is exceeded, request that a body image be provided for use in generating a second body image of the body.
 13. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors further cause the one or more processors to at least: receive a second 2D face image of the face of the body; process the second 2D face image to determine a second face-based body feature corresponding to the first existing body feature; determine that a difference between the second face-based body feature and the first existing body feature exceeds a threshold; and in response to determination that the difference exceeds the threshold, request that a body model of the body be generated based on a body image.
 14. The computing system of claim 7, wherein generation of the updated first body feature is determined based at least in part on one or more of: a first neural network trained based at least in part on face images to determine face-based body features of bodies corresponding to the face images; a second neural network trained based at least in part on face images and corresponding body images to determine face-based body features corresponding to the face images; or a third neural network trained to determine the first existing body feature.
 15. The computing system of claim 7, wherein the program instructions that when executed by the one or more processors further cause the one or more processors to at least: apply a texture to an updated body model generated based at least in part on the updated first body feature and the updated second body feature, wherein the texture is determined based at least in part on the 2D face image.
 16. A method, comprising: generating a plurality of face-based body features for a body corresponding to a face represented in a two-dimensional (“2D”) face image, wherein: the body is not represented in the 2D face image; and at least one of the plurality of face-based body features corresponds to an existing body feature of the body that was previously determined for the body; determining at least one of a difference or a ratio between the at least one of the plurality of face-based body features and the existing body feature to which it corresponds; updating, based at least in part on the face-based body features, the existing body feature of the body to generate an updated first body feature; updating, based at least in part on one or more of the difference or the ratio, a second existing body feature of the body to generate an updated second body feature; and presenting, at least the updated first body feature and the updated second body feature.
 17. The method of claim 16, further comprising: applying a texture to at least a portion of an updated body model generated based at least in part on the updated first body feature and the updated second body feature, wherein the texture is determined based at least in part on the 2D face image.
 18. The method of claim 16, wherein generating the plurality of face-based body features includes: applying a bias correction to account for a bias in generating the plurality of face-based body features compared to generating body features from a body image.
 19. The method of claim 16, wherein generating the plurality of face-based body features is based on a plurality of 2D face images of the face from different perspectives.
 20. The method of claim 16, wherein: at least some of the plurality of face-based body features correspond to features of a plurality of existing body features of the body that were previously determined; and updating includes updating at least some of the plurality of existing body features with at least some of the plurality of face-based body features. 